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Essay 296 - Downs syndrome screening

Posted by Sophia Y.
A 39 year old woman has been referred to the antenatal clinic at 10 weeks gestation. She is worried about having a baby with Down’s syndrome.
(a) Describe how you will assess her risk of having a baby with Down’s syndrome [6 marks].

Her risk adjusted to age is nearly 1/100. Her risk of having a baby is higher if she has a baby or babies with Down\'s syndrome.
Babies born with Downs syndrome usually have trisomy 21. She has an increased risk if she or her partner has chromosomal translocation involving chromosome 21. The risk will also be higher if she or her partner actually have Trisomy 21.

(b) She has a 1 in 25 risk of having a baby with Down’s syndrome. Discuss your counselling and subsequent management [14 marks]

I will explain to her that baby born with Down\'s syndrome can have a range of medical, cognitive & behavioural problems. These include congenital heart diseases, duodenal atresia, hypotonia, learning difficulties and leukemia.

I will counsel to her +/- partner about the results of the screening tests very sensitively as it can cause alot of distress and anxiety. I will explain to her our cut-off point of regarding high-risk of having Down\'s syndrome is 1/250, therefore she is regarded to be at high risk. The definite way to confirm whether her baby has Downs is by checking the fetal karyotype by chorionic villus sampling (CVS) or amniocentesis.

I will explain to her that CVS is normally done between 11-13/40. It allows early diagnosis so that surgical termination may be feasible if result can be obtained before 12 weeks + 6 days. However it is associated with a slightly higher risk of miscarriage (2-3%) than amniocentesis (1%). There is also a small risk of placental mosaicism and bloody tap. Amniocentesis is normally done between 16-18/40. Both of them will be done under continuous USS guidance with trained operators. There is a risk of failure to obtain sufficient sample, infection & feto-maternal haemorrhage for both techniques. The result can be analysed by PCR and obtained with 2-3 working days to identify trisomy 21. It will not be able to identify other rare syndrome. Our local obstetric unit will contact once the result is available ie 2-3 working days. Culture will take about 2 weeks. She will need to receive Anti-D if she is rhesus negative within 72 hours after the prenatal diagnostic test.

I will offer her for CVS or amniocentesis, pending what gestation she decides to have it done. I will refer her to our feto-maternal specialists who have trained to perform these tests. If it confirms T21, I will offer her termination of pregnancy. I will give contact phone numbers of counsellors or specialist midwives if needed for emotional support.

If she declines prenatal diagnosis or declines TOP despite baby being affected & wishes to continue the pregnancy, i will respect & support her decision. Therefore I will refer her to feto-maternal specialists for detailed anomaly scan. Should there be any significant major structural anomalies, i will refer her to the paediatric surgeons to discuss about possible corrective surgery & prognosis. She will need serial growth scan at 28, 32 & 36 weeks gestation as there is a risk of IUGR and stillbirth. Neonatalogist need to be involved during the delivery & postnatally. I will also give her written leaflet on prenatal diagnosis (amniocentesis & CVS), Downs syndrome & support group for Downs syndrome.
Posted by Johnson  O.
A/
Reasons for her worry is important. This may be due to her age. Risk at this age is about 1 in 100. I would ask about any family history of Down syndrome which would increase her risk further. If she is multiparous, any previous history of baby with Down syndrome. History of previous miscarriage and if any cytogenetics investigation done , most especially in recurrent miscarriage which may due to chromosomer abnormality.
I would offer her screening test to assess risk of Down syndrome. First trimester test involve serum BHCG and pregnancy associated plasma protein A. This can be combined with Ultrasound scan for Nuchal fold tickness around 11 to 13 weeks gestation. First trimester screening allow early decision on the pregnancy either continuation or termination of pregnancy.
other option is to offer second trimester screening test from 15weeks gestation. In Double test serum BHCG is high with low alphafetoprotein suggesting high risk for Down Sndrome. with sensitivity of 60%. Triple test include Unconjugated Estriol with Double test, sensitivity is 68%, and quadriple test is serum inihibin A with triple test with sensitivity of 76%.
B/
I would inform her about the findings in a sympathetic and sensitive way, because, it will generate more anxiety. I would tell her that she has 1 in 25 chance of having baby with Down syndrome, which means that 24 out 25 chance of baby been normal. I would offer her the option of Diagnostic test to confirm Down syndrome or continuation without test.
I would inform her that Chorionic Villious sampling can be done around 11 to 13 weeks of gestation. It involve taking sample from the placenta tissue. It would be sent for karyotyping. The initial result would be ready in 48 hours using FISH technique, final results in 2 to 3weeks. There is 1 to 2% risk of miscarriage.
Amniocentesis can be done from 15weeks gestation. It involve taking amniotic fluid for karyotyping. Miscarriage rate is lower at 0.5 to 1%.
It is important to discuss her decision if the result comes back as Down syndrome. I would offer her the option of termination of pregnancy or continuation of pregnancy with the full understanding of complication which include cerebral palsy, low high IQ, congenital heart defect. multiple abnormalities.
If she want to continue with the pregnancy, she would be managed at the fetomaternal unit. I would arrange detailed anomaly scan at 18-20weeks gestation for Down syndrome specific abnormality like Cardiac defect, abdominal wall defect, limb hypoplasia. fetal echocardigram at 22 weeks gestation.
Serail growth scan because of risk of Intrauterine growth retardation.. Multidisciplinary involvement in her care including paediatrician who will discuss with her about neonatal care. I would aim for vagina delivery. Caeserian section for obstetric indication only.
I would provide her with written information leaflet to enable her make well informed decision. I will provide Counselling and Support group.
After delivery, postnatal clinc to discuss future pregnancy and risk of recurrence. Breast feeding is not contraindicated.
Posted by Ajith S.
A--
I will inquire regarding why is she worried? She may be worried as she is 39yrs old or with other background issues in the family or in past experiences with Recurrent Miscarriage/Foetal death in Utero and Downs baby in family. I will ask that she or her partner has any chromosomal abnormality like balance translocations. I would like to know whether this pregnancy is singleton or multiple pregnancy and how accurate her dating of pregnancy. If her dating is accurate and singleton pregnancy with no other medical problems like IDDM, I will explain her age related risk is high:about 1/100. This risk can move up or down depending on other test parameters. I will discuss the available screening tests- I will explain that screening test does not exclude Down’s syndrome but categories her risk status. 1st Trimester serum screening between 10-14/40 with Free Beta HCG & Pregnancy associated Plasma Protein- A with ultrasound measurement of Nucal fold thickness between 11/40 3-13/40+6 and her age together will give 90% detection rate with 5% false positive rates. As this is an early test they will have time to decide for Surgical termination if they want .If this test come as high risk I will offer a confirmatory test. Other screening test is 2nd trimester serum screening 14-21 weeks, this is only a blood test –check for few markers and then calclculate risk status. Markers are low AFP, high free Beta HCG, low Oestriol and high Inhibin A levels. Depending on number of markers tests test accuracy is deferent this will detect 50- 76% of downs babies’ with 5%false positive rate. As this screening test will not give definitive answer this may generate extra anxiety and some time she may decide that she will have confirmatory tests straightaway.


B--
I will asses her knowledge about Down’s syndrome and explain that child with Down’s syndrome can have range of medical, surgical, cognitive and social issues which need to have corrective surgical procedures, medications and other special care needs.
I will explain that 1/25 chance means 24/25 chance of having normal baby and as this is high risk we will offer confirmatory test to definite diagnosis of chromosomal abnormality of down’s syndrome but not all other chromosomal or genetic abnormalities. As confirmatory tests were invasive procedures and done under ultrasound guidance and has small risk of miscarriage. She may need Anti D within 3 days if she is Rhuses negative. Confirmatory tests are CVS-chorionic villas sampling between 11/40-13/40 where small tissue samples of placenta for testing of chromosomal status. CVS give us quick result with FISH in 48hrs but cell culture will take 2/40 to confirm the early results. There is risk of miscarriage of 1%,Chromosomal mosaicism of 0.5% and very small risk of bloody tap and culture failure in this cases she may need Amniocentesis.
Amniocenteses done under ultrasound guidance after16 weeks where about 15ml of fluid around baby from uterus will sent for testing -FISH for quick test with in 48hs with formal cell culture will take 2 weeks Risk of Miscarriage is about 1/200.Small risk of cell culture failure.
In case where chromosomal abnormality confirmed down’s syndrome patient can decide to continue or Termination. If she decides to terminate pregnancy will be medical termination of pregnancy.If patient decided to continue pregnancy I will respect and support her decision and arrange to have Morphology ultrasound after18 /40weeks and cardiac scan after 24/40.If results exclude down’s syndrome I will explain that she need to have morphology scan as there can be other structural abnormalities, which is not related to chromosomal abnormality.
If there is any abnormality I will refer for relevant medical subspecialists ex Paediatric Surgeons, Neonatologists
I will refer her to counsellor and other relevant obstetric care groups, and provide some support groups contact details.
As Down’s syndrome pregnancies can have IUGR need to have growth scan after 28, 34 weeks. I will advice her to have Hospital delivery and will inform neonatologist at delivery and immediate postnatal care.
Posted by H H.
She is 39 y old, so her background risk of Dowen syndrome depending on age alone is less than 1 per 100.I would ask her if she had a previous baby affected by Dowen or family history of Dowen which will increase her risk.Has she or her partner had any karyotype screening for translocation type Dowen or referral to a genetic counsel for risk assessment. There are screening tests that will help in more accurately assessing her risk taking in consideration ,her age,weght and gestational age.The most efficient,cost effective and safe (less number of loss of normal pregnancies from diagnostic procedures due to low false +ve rate of the test),would be the integrated test using maternal serum markers ,PAPP-A at 10 wk gestation, b HCG,alpha feto protein and inhibin at 16 to 18 wk in addition to urinary estiol and nuchal thickness NT by ultrasound at 13 wk gestation.This gives a false +ve rate of 1.2% for a detection rate of 85%.The serum integrated test uses all parameters except NT and has false +ve rate of 2.7% for the same dtection rate(Surrus study). The most early screening test that is done in first trimester would be the combined test using serum PAPP-A at 10 wk,bHCG and NT this gives a false +ve rate of 6.2% for a detection rate of 85% ,this will give a risk figure for couples needing to know at an early gestation so that diagnostic tests done early and early termination if they wish. The quadrible test done at 16-18wk give the same false +ve results and detection rate like combined test using maternal serum bHCG, alpha fetoprotein ,inhibin A and urinary estriol.Other tests have a high false +ve results and include NT( which can be the best parameter where serum markers can not be used eg in multiple pregnancy,diabetes and gross obesity) , triple test( bHCG,alpha feto protein ,u estriol) and double test(b HCG alpha fetoprotein).

B.Sympathetic counseling is done taking in consideration her anxiety. I would explain to her what 1:25 risk mean ie in every 25 cases,24 will be normal and one will be affected.So it is not confirmative and to confirm will need other tests.Will explainto her what is Dowen( intellectual affection,low intelligence, long survival,medical problems that can be acute oe chronic including cardiac and renal, structural problems,dependance on society despite some may not with help of supportive socities,increased risk of thyroid problems, epilepsy,leukemia and Alzheimer later in life.
I would see to her attitude to an affected child. Would discuss with her confirmatory tests ,which at her gestation would be chrion villus biopsyCVS ,explain how done(needle inserted under ultrasound guidance reach placenta) ,what for(to obtain fetal material for chromosomal analysis) , tell her that there is risk of miscarriage of 1-2per 100 procedures , risk of infection one in one thousand cases ,risk of culture failure or failure of the procedure 1 in 200.Doing this test will allow her an early termination if test prove +ve for Dowen. Will tell her that Amniocentesis mean taking amniotic fluid at 16-18th wk gestation for cytological investigation . It is more safer procedure than CVS regarding risk of miscarriage 1:200 but has to be done at a later gestation.
If patient decides that she will continue with the pegnancy any way, then confirmatory tests with their problems are not adviced unless patient wants them done to plane her life.Anyhow the usual antenatal care is done with aid of multidisciplinary team including neonatologist, pediatric surgeon ,support groups.Plan delivery as usual unless adviced by fetal therapy team or pediatric surgeon.Give written information and address of Dowen association group.
If patient would like to terminate an affected fetus, will discuss with her methods of termination and that at early termination either surgical or medical termination can be done.In later gestations as when diagnosis done by amniocentesis, usually medical termination done and fetal heart is first stopped by injecting a substance into the cord.Will do bereavment counseling and discuss burial procedures. Will discuss her risk of Dowen in future pregnancy and genetic counseling for risk in case of translocation Dowen.
Posted by Leen K.
LEEN
A 39 year old woman has been referred to the antenatal clinic at 10 weeks gestation. She is worried about having a baby with Down’s syndrome. (a) Describe how you will assess her risk of having a baby with Down’s syndrome [6 marks]. (b) She has a 1 in 25 risk of having a baby with Down’s syndrome. Discuss your counselling and subsequent management [14 marks]

(a) History taking is an important part of assessing her risk, as higher maternal age is associated with increased risk of having a baby with Down\'s Syndrome (DS). As she is 39 years old, her risk would be < 1:100. History of having a previous baby with DS also increases her risk. I would also enquire about whether she or her partner is known to have a balanced translocation.
Screening helps to individualise the risks of having a DS baby further. The combined screening, which involves a nuchal translucency scan and checking free-HCG (human chorionic gonadotrophin) and PAPP-A (pregnancy associated plasma protein - A), is performed in the first trimester(TM). It detects 85% of DS babies with a false positive rate of approximately 6%. Thus false positive rates may be decreased to 1.2% if combined with quadruple serum screening in the second TM (this involves checking levels of unconjugated oestriol, alphafetal protein, freeHCG and inhibin) However, adding the second trimester screening means that the result of the screening will not be available until the second TM. The combined test alone has the advantage of having its results available in the first TM, this allowing more time and options for diagnosis (if required) and intervention (eg termination of pregnancy (TOP)).

(b) I would explain to her that this figure is a risk estimate, and not a definitive diagnosis; and out of 25, she has 24 chances of having a normal baby. I would make sure she is seen by the hospital counsellor that normally deals with these patients (usually a midwife that has a special interest in counselling for CVS (chorionic villus sampling) or amniocentesis, and chromosomal abnormalities).

Most units will offer diagnostic tests at these risk levels, and I will offer her CVS if she is in the frist TM, and amniocentesis if she is in the second TM (can be done safely after15 weeks). I will explain that these are definitive diagnostic tests, but they do have some risks. There is a risk of iatrogenic miscarriage of 2% with CVS, and 1% with amniocentesis. There is also a risk of infection and rupture of membranes. She should be properly counselled about what each procedures entail (local anaesthetic, and ultrasound guided needle aspiration of placenta or amniotic fluids, in CVS and amniocentesis respectively), and written information given on DS as well as these diagnostic procedures.

If she does decide to have CVS or amniocentesis, she should be counselled that a preliminary report will be available within 48 hours and a full report (that also checks for other chromosomal abnormalities) tend to be ready in a week.

If she is found to have a normal baby, then no further intervention or monitoring is required. If be baby is diagnosed as having DS, I would explain that DS babies may range from being just mildly affected and leading a near normal life, to some with severe disability. TOP should be offered as an option, and it is the patient\'s choice whether she wishes to procede with the pregnancy. If she does, then an anomaly scan looking for soft markers and structural abnormalities (at approximately 20 weeks) may help guide counselling and decision about TOP, or continuing the pregnancy. If the baby has structural abnormalities (eg, cardiac defects, exomphalus ), input from other specialists such as neonatologists or paediatric surgeons should be sought; and antenatal monitoring and delivery should be planned on an individual basis.

Written information (such as about DS, diagnostic tests, TOP ) should be provided to back up counselling at each step of the way; and contact information of support groups should be given to the patient (eg Down Syndrome Association).
Posted by robina K.
9A) Risk assessment for down syndrome is done on the basis of Age, previous baby with downs syndrome, results of screening tests and parenteral karyotype abnormality like translocations which are balanced translocations , Robertsonian or Reciprocal. The prevalence of Downs syndrome is 1 in 700 of live births.Recurrent risk is 1 percent for the sporadic cases.Risk increases with age such as at 39 years the risk is 1 percent.Risk is further increased if the screening tests become positive and the parents have unbalanced translocation.The most common screening test offer is Nuchal translucensy between 10 to 13 weeks .A cutoff level of 3.5 mm is taken .More than this is cosidered as a positive screening test.NT has a sensitivity of 80 % but a very high false positive results of 20% .NT can be increased in a number of other conditions like cardiiac, turner syndrome,cystic hygroma and hydrops fetalis, however in the majority of cases the outcome is normal. If NT is increased I will offer her other screening tests which at 10 weeks gestation could be combine test which constitutes NT, Free Beta HCG and PAPP-A estimation. This screening test has a sensitivity of 85% with a false positive rate of about 5.5 to 6.5 %. Other screening tests like integrated and serum integrated tests are performed in first and second trimesters ,though the false positive rates are the lowest (1-3%) , to wait till 14-20 weeks for the second part of test will be quite late if TOP is needed.Therefore I will recommend her combine test which if positive I will offer her CVS.

(B) 1 in 25 is a very high risk which is going to arise severe anxiety in the woman.The news should be disclosed by an experienced Obstetrician in the presence of her partner, other family members or a close friend.She is informed about this risk with reference to the back ground risk in a sympathetic and supporting way. I will tell her that Downs Syndrome is associated with severe mental retardation , learning disability and structural anomilies like cardiac defects, gastrointestinal abnormalities , urinary and limb defects.Time should be given to assimilate the news with the offer of further support, counselling and further management.I will tell her that for definite confirmation Karyotype is necessary which at this stage can only be done by CVS.I will explain her the procedure like it is done between 11 and 13.6 days via abdominal or vaginal routes under local anesthesia and ultrasound guided.Results can be obtained with in 24 to 48 hours.I will discuss with her the options and implications of a positive result , in fact I will discuss TOP in case of a positive result, in fact I will not recommend CVS if she shows her unwillingness to TOP ,because CVS is associated with a miscarriage risk of 1-2% over the background risk.In such situation I will offer her routine anomaly scan at 18 weeks gestation though anomaly scan is not going to diagnose Downs.If she agrees for CVS I will refer her to fetal medicine centre.In case of an abnormal karyotype I will discuss the timing and methods of TOP. I will advise her the TOP as soon as possible due to complications if performed late.At 10 weeks of gestation the most appropriate method is surgical evacuation with prostaglandin priming of cervix if it is tightly closed. TOP may be performed under local or GA.The risk of haemorrhage, infection, perforation and continuation of pregnancy should be discussed though these risks are very small in experianced hands.l will also discuss chlamydia screening or prophylactic antibiotic. Risks for thromboprophylaxis is assesed.The procedure is usually performed as a day case and rarely admission is needed.I will offer her further counselling and support groups like british Down syndrome association.
Posted by Dr Saritha M.
a)
I will explain the risk of baby having Downs syndrome with her age will be around 1in100. Enquire about the family history and previous child has the Down syndrome as the risk increases if history is positive and if required parental chromosomal analysis for translocation is advised as t(21,21)has got 100% risk compared to (14,21). Woman is offered a screening test after 11weeks after assessing the accurate dates. The test involves serum testing for HCG and PAPP-A and ultra sound measuring nuchal translucency a combined test. It has a detection rate of 85% and fase positive rate of 6%.I will also offer a screening test at 15+o weeks an Integrated test a combination of HCG, AFP, uE3, inhibin A and NT, PAPP-A which has got a false positive rate of 1.2%.
b)
I will explain the risk of 1 in 25 is on the higher side but a further test to be carried out to confirm this and offer a invasive testing chorionic villous sampling or Amniocentesis which tells the definitive risk. The procedure related loss of 1% is also explained. the result will take around 48 hours. If the result is negative woman is reassured and offer anomaly scan at 18-20 weeks. If the result is positive appropriate counselling is done and referral to Fetomedicine specialist is done. Woman is told about that Downs baby have cardiac, gastrointestinal, renal anomalies and low IQ.Average life span will be around 50yrs. Requirement of major surgery following delivery is expainled.
Womans wish regarding continuation of pregnancy is considered if she is willing then detailed anomaly scan is carried out in a tertiary centre .If two or more anomalies present then offer termination after counselling.
The method of termination has to be explained. If she is continuing pregnancy delivery is carried in consultant led unit with the availability of neonatologist and paediatric surgeon and midwife.
Information leaflets are provided. counselling is carried with invovlement of husband and or family members. Recurrence rate is explained. Referral to genetic specialist is done.
Posted by Manoj M.
A 39 year old woman has been referred to the antenatal clinic at 10 weeks gestation. She is worried about having a baby with Down’s syndrome. (a) Describe how you will assess her risk of having a baby with Down’s syndrome [6 marks]. (b) She has a 1 in 25 risk of having a baby with Down’s syndrome. Discuss your counselling and subsequent management [14 marks]

M
(a)
She has an age related risk of approximate 1 in 100, but this may be different with screening tests.
If she has a previous pregnancy affected with Downs syndrome this will increase her risk in the current pregnancy.
If one or more relative affected by downs syndrome this may increse her current prgnancy risk.
A first trimester screening with nuchal translucency done from 11 to 13+6 weeks pregnancy along with serum PAPP-A and hCG has a detection rate of 90% with 5% false positivity.
Along with this other first trimester soft markers like absent nasal bone, triscuspid regurgitation may increase the risk of downs syndrome.
Integrated second trimester biochemical screening with first trimester NT will have a similar detection as first trimester screening with a lower false positivity.
Anomaly scan at 18-20 weeks may also detect markers i.e. more than one may suggest incresed risk for downs syndrome.

(b) This is likely to be extremely anxious parent or couple.
She or they must be counselled by an Obstetric consultant or fetomaternal specialist.
The counselling should be with protected time clinic with supportive staff or relatives offered for the patient.
Explain to her this is screening test results and not diagnostic, and 1 in 25 risk of downs syndrome also means 24 out of 25 are normal babies.
She will be offered diagnostic testing to detect fetal karyotype and her choices will be considered, she may also choose not to do any diagnostic test.
The available diagnostic tests include chorionic villous sampling(CVS) and this will be done from 10 completed weeks of pregnancy and done ultrasound guided by fetomaternal specialist.
CVS has an approximate 2% risk of procedure related miscarriage and 1% risk of mosacism. This involves taking placental tissue for karyotyping.
The other diagnostic testing is called Amniocentesis and this will be offered from 15 completed weeks of pregnancy and one ultrasound guided.
Amniocentesis has approximately 0.5-1% risk of procedure related
miscarriage and involves taking amniotic fluid sample for karyotyping.
The karyotype results can be obtained with FISH test by 24-48hrs and a complete culture result by 2-3weeks.
She will be provided with the local cytogenetic lab details, storage and failure rates.
If she is rhesus negative she will be offered anti-D prophylaxis with invasive procedures.
The test may detect down syndrome or other chromosomal abnormalities like Trisomay13 and 18.
If a chromosomal abnormality is detected she can choose with the information to prepare for the pregnancy or proceed with termination of pregnancy.
After CVS she may be suitable for surgical termination but after Amniocentesis she may need medical methods and go through labour.
She will be provided with written documentation or tape of consultation and opportunities to answer any querries or a followup appointment.
Posted by SANCHU R.
A 39 year old woman has been referred to the antenatal clinic at 10 weeks gestation. She is worried about having a baby with Down’s syndrome. (a) Describe how you will assess her risk of having a baby with Down’s syndrome [6 marks]. (b) She has a 1 in 25 risk of having a baby with Down’s syndrome. Discuss your counselling and subsequent management [14 marks]

a)Her age -related risk should be determined. At 40 years, the age-related risk is 1 in 100. Therefore her risk would be less than that. Risk by Ultrasound by measuring Nuchal translucency (11-14 weeks) and Biochemical screening by measuring Serum beta HCG and PAPPA are assessed which give a combined risk assessment. This first trimester screening has a 85% detection rate with a false positive rate of 5%. The Integrated test which combines the first trimester screening with the second trimester (15-20 weeks)Quadruple test of measuring serum beta HCG, estriol, AFP and Inhibin A improves detection rate by 95%.

b) If the risk assessment is based on first trimester screening, she should be told that it is just a screening test which is not diagnostic and can be false positive. The diagnostic test of Chorionic Villus Biopsy should be offered explaining the risks involved. It can be done at 10- 13 weeks. It has a risk of miscarriage which is 2 in 100. It can be uninformative if there is mosaicism in the sampled tissue. The other risks are RH isoimmunisation nad infection. But the benefit is that, since it is a first trimester test, termination of pregnancy is easier and safer for the patient and the physician.
The other option would be an amniocentesis done at 15-20 weeks which has a lower miscarriage rate of 1in 100. There is no problem of mosaicism. The disadvantage is the anxiety due to waiting till the 2nd trimester and the more difficult termination of pregnancy compared to first trimester. The other risks would be amniotic fluid leaking and infection. If these tests are inconclusive, fetal blood sampling may be required. She must also be informed that it takes 1-2 weeks for the results and written information should be provided.
Posted by Ron C.
RnRn

A.
Initial assessment by means of history taking; positive family history or previous children with Down’s or perhaps unbalanced translocation in her or her partner. Vast majority (>95%) of cases though is “the-novo” mutation.
Her background risk for age is around 1:40, but can more precisely estimated by doing serum testing for beta-HCG, AFP & E2 in 1st and 2nd trimester and scan for nuchal translucency around 12 weeks. Based on these findings risk assessment is made with correction for maternal age. With a cut-off of 1:250, this combination of test will identify 83% of cases with 6% false negatives if done in 1st trimester only, 1.2% if combined 1st and 2nd trimester. If risk above the threshold, it is justified to offer chorion-villi biopsy around 13 weeks, or amnion-punction from earliest 16-17 weeks onwards, as risk for iatrogenic pregnancy loss is respectively 0.5-1% and 0.5%. If she is not keen for CVB or AP, than she can be scanned at 20 weeks to look for soft markers, though this will pick up less cases and is not very specific.

B.
She must be told this doesn’t mean her unborn child has downs, but rather that the risk for this is higher than expected based on her age. She must be fully aware what Down’s means in terms of having a child with mental restricted capacity, requiring life-long care, shortened life-span and with comorbidities such as atrium-septum defect being common. It is good to discuss beforehand what she’d like to do if test turns out positive for Down’s; termination only possible up to 24 weeks, in second trimester termination by means of Mifepristone and cervagem as compared to late termination after 20 weeks. She must take into account that a number of pregnancies with down would miscarry anyway, an that spontaneous miscarriage may be emotionally less taxing than having to go for pregnancy termination. She must be told that earliest available test is chorion villi biopsy around 13 weeks, with documented limb defects if too early and iatrogenic pregnancy loss in 0.5-1%, if transcervical up to 2%. Amnion punction is only possible from 16 weeks onwards, with iatrogenic pregnancy loss 0.5%, often due to infection or leaking liquor. She must know about possibility of false negatives or positives, such as in mosaicism. Karyotyping by means of FISH will yield results as fast as within 72 hours and can identify numbers of chromosomes only, such as 13, 18 and 21. PCR will take longer, but gives additional information about the form of chromosome. I will give her further written information to read up.
Posted by Shalini  M.
it is important to begin by taking a history of an affected individual in the family.She should be explained about screning tests which are not diagnostic but suggest an increased risk of trisomies and necessitate further invasive tests which are diagnostic.She should be offered Integrated test (detection rate of 90%and a false positive rate of 2.8% )which includes NT and PAPP_A at 10 weeks and free b-hcg,AFP,ue3 at 14-20 weeks.If however the estimation of NT is difficult due to obesity or abnormal fetal position then serum integrated test can be offered including PAPP-A at 10 weeks and free b-hcg,AFP,ue3 at 14-20 weeks with a detection rate of 85% and a false positive rate of 2.7%.The results of these tests have to be waited for till second trimester when the test starts in first trimester prolonging the agony of the lady.Also it delays the decision to terminate and affected pregnancy if so desired by the lady to the second trimester.Thus,if first trimester screening is desired combined test(detection rate 85%with 6.1%false positive rate) includind NT,Free b-hcg,PAPP-A at 10weeks can be offered.However if she deisres a test in the second trimester then quadruple test(detection rate of 85%with false positive 6.2%)including AFP,b-Hcg,ue3,inhibin A and also the triple test(85%detection rate with false positive of 9.3%)including AFP,b-hcg,ue3 at 14-20 weeks can be offered.
b)It is essential to sympathetically explain the increased risk to the couple and the need to confirm it with invasive tests.She should be offered support as this could be devastating to her.She should be explained the association of Down\'s syndrome with cardiac malformations(ASD),GI anomalies(Duodenal atresia),renal anomalies other than subnormal intelligence and increased risk of developing leukaemia,thyroid disorder,alzheimer\'s disease and epilepsy.It is thus essential to confirm this disorder by invasive tests like CVS,Amniocentesis,Fetal blood sampling.CVS can be done transabdominally at 11 weeks and has a 1-2%risk of miscarriage as also 1%risk of placenatl mosaicism that needs to be confirmed by amniocentesis.Amniocentesis can be done at 15-20weeks under ultrasound guidance transabdominally and has a 0.5-1% risk of miscarriage as also increased risk of infection.fetal blood sampling is done at 18-20 weeks and is not preferred at this indication due to high risk of side effects like bleeding,cord haematomas,fetal bradycardias,intrauterine deaths.Use os FISh and fluoroscent labelled probes enables test results in 3 working days.CVS has the advantage of earlier diagnosis and earlier termination if pergnancy is affected.If results of invasive testing are positive then the couple needs further counselling and termination should be offered.If desired it could be done medically or surgically.If continuation of pregnancy is desired then they should be referred for genetic counselling and paediatric counsultation.They should be asked about no monitoring in labour to avoid cesarean section and no active resuscitation of the newborn.Also neonatologist to attend delivery.They should be informed about support groups.
Posted by A A.
PART A
As she is 39yrs old her age related risk is about 1:150 at term.95% Down syndrome are due to trisomy21 and only 4% are due to translocation involving chromosome21.Iwill enquire whether she or her partner is having Downs syndrome or are known to have chromosomal translocations. Any previous pregnancy with Downs baby and family history,because any of these factors increases likelihood of Downs Syndrome.Further risk assessment will be based on screening test results.A range of screening test are available.I will offer combined test as it is done early between 11-13 weeks and involve nuchal translucency,PAPP-A and free BHCG with 85% detection rate but high(6%)false positive rate.Its advantage is that it is a single point test.Other tests like Integrated test(NT plus PAPP-A at 10wks and AFP,UE3,freeBHCG and inhibin A at 14-20wks)is most effective test with 85% detection rate for only 1.2%false positive rate but it involves both first and second trimester screening and delay in further management.Other test like Quadruple test,triple test and double test are 2nd trimester screening test with high false positive rate.
PART B
I will ensure that test result is accurate by ascertaining her gestational age.As test results are likely to create anxiety,my approach would be sensitive,supportive and empathic.I will explain to her that screening only identifies whether a particular baby is at risk of Down Syndrom, but it does not provide definitive diagnosis.There is only 1 chance out of 25 of having downs baby. For its confirmation diagnostic tests are available which are more invasive, expensive and are associated with complications. I will explain that there is a spectrum of Downs Syndrome abnormalities including risk of miscarriage, IUD, structural abnormalities like congenital cardiac defects (AV Canal), GIT defects(like duodenal atresia),limb defects,congenital cataract and urinary tract defects. On birth appearance of the baby is like having slanting palpebral fissuras, epicanthic folds, open mouth with protruding toung. There will be learning disabilities and long term risk of thyroid disorder, leukaemia, Alzheimer’s disease and epilepsy. Life expectancy is between 50-55 years, so long term care is required. But all babies with Downs Syndrome do not have all of these features, they vary in it ranging from mild to severe. I will offer diagnostic test like chorionic villus sampling. It is performed after 10 weeks by transabdominal or transcervical route with early report within 48hrs by FISH/PCR technique but culture results within 2-3wks. There is a risk of miscarriage 1-2% above background risk, placental mosaicism 1%, infection and rhesus immunisation.It provides opportunity for easy and early termination of pregnancy which is less traumatic both psychologically and procedure related. Other options is amniocentesis performed after 15 weeks of gestation transabdominally. It is associated with 0.5 to 1% risk of miscarriage above background risk, culture failure 0.5%, infection and rhesusisoammunisation. If the test results are negative I will reassure the patient and rest of the pregnancy will be managed as a routine. If the test results are positive I will explore the patient’s attitude towards pregnancy whether they want to continue or terminate it.If they are willing for termination of pregnancy I will discuss different methods of termination (medical/surgical) with benefits and risks explanation. If they want to continue the pregnancy, I will respect their wishes and provide support in their decision. I will provide the information about Downs Syndrome parenting, contact details of support groups like Down’s Syndrome association and Downs’ Syndrom medical Interest Group and written information of above detail.I will offer detail anomaly scan at 20wks to look for structural anomalies like cardiac,GIT, other defects,and Soft markers like choroid plexus cyst, echogenic bowl associated with down syndrome. It will help in further counseling of the parents and they can review their decision about pregnancy. In case of cardiac and GIT defects serial growth scans and liquor volume will be done after 28 weeks of gestation for early detection of complications. I will involve neonatologist, paediatrician and pediatric surgeon to discuss the fetal/neonatal prognosis with parents and postnatal management. I will also discuss the recurrence risk and referral to the geneticist for genetic counselling. I will discuss the place,mode of delivery and criteria for intrapartum intervention for fetal reason with parents. Aim is for vaginal delivery. Neonatologist should be present a the time of delivery for the detailed assessment of the baby. In the post partum I will discuss contraception before discharge and plan for subsequent pregnancy.

eriod I will discuss the contraception before discharge and the plan for subsequent pregnancy.
Posted by dr anis urrehma R.
her risk of down syndrome can be assessed base on her age ,first trimester bichmical screening ,nuchal transluscency measurement between 10-13 weeks gestation or second trimester biochmical method.done alone these all methods have low sensitivity with high false positive rate.combining ist trimester biochmical screening with nuchal transluscency gives better sensitivity.further combining it with 2nd trmester quadruple test and age related risk improves it further with low false positive rate thus reducing the number which will need invasive testing and pscychological morbidity.
the result of 1;25 is going to the patient very worried and likely to put her in exreme anxiety.so the result need to be conveyed to her in a sympathetic way by a person who is experienced to do so.i will counsel her that still she has more chances of having a baby without down syndrome.there are diagnostic test available which will help us know with more certanity about the baby having down syndrome. i will counsell her about invasive techniques of prenatal diagnosis that is amniocentesis and CVS.i will inform her that procedure related miscarriage rate is 1% AND 2% respctively.the other noninvasive tehnique is the use of free DNA in maternal circulation .the advantage as the non invasive nature of the test thereby limiting morbity .i will discuss with her the time after which the result will be available and about her plans in case the baby is diagnosed with trisomy 21.further mangement will be dependent on the result of diagnostic testing.if patint chooses to terminate the pregnancy or plans to continue in both cases she will be supported in her decision.miscarriage arranged in first case with followup visit and a support group.if she chooses to continue pregnancy she will need to understand the special needs so liasion with neonatologist for the rest of pregnancy will be done.infomation about the support group will be given.
Posted by SA M.
a) Her age risk of having Down\'s syndrome baby is around 1:100.Her parity is important because she has a baby with down\'s syndrome then in current pregnancy her risk of having down\'s syndrome baby will increase.95% of down\'s syndrome occurs due to non disjunction of chromosome 21 and around 10% due to translocation.If she has a 14:21 translocation risk of recurrence is 1:10 and if her partner has this translocation risk of recurrence will be 1:50.Her risk of having Down\'s syndrome baby will increase if she has an immediate family member with down\'s syndrome.
Her risk can be assessed by doing screening test for down\'s syndrome which include firest trimester screening through Nuchal translucency between 11-13 weeks gestation when combined with maternal age has a detection rate of 85% with the false positive rate of 20%.other screening test is ist trimester includeNT,PAPP-A and free BHCG with maternal age relared rick associated with 85% detection rate and 6.1% of false positive rate.Advantage of ist trimester screening is early detection with early decision regarding termination of continuation of pregnancy.She can go for combined ist & 2nd trimester screening where integrated test has been 85% detection with false positive of 2.1% include NT & PAPP-A in ist trimester & alpha Fetoprotien,Serim estradiole,Inhibin A,BHIG in second Trimester.Second Trimester screening test from 15 weeks onwards include double, triple & Quadruple test where BHCG +alpha Fetoprotein in double test with addition of unconjugated estradiol in triple test and addition of Inhibin A in quadruple test with detection rate of 85% has false positive of 13.1% for double .9.3% for tripple & 6.1 for quadriple test respectively.

b) I will tell her in a sympathetic & sensitive way that she is at high riskof having a Down\'s syndrome baby from her risk assessment as cut off is 1:300.But this is not a confirmatory test.For Confined diagnosisshe needs invasive testing if she wishes.These tests include chorionic villous sampling between 11-13 weeks gestation where through her abdominal under Ultra Sound cells from placenta will be taken and test chromosomal aanalysis.Early results can get with FISH technique but final results in about 3 weeks.Risk of miscarriage is 2-3 % and also risk of placental mosaicism is there e CVS .Advantage of this test is early confirmation of diagnosis with early decision of termination or continuation of pregnancy.Other option is 2nd 2nd trimester Inpasive testing known as Ammosentesis from 15 weeks onwards under ultrasound guidance Ammiotic fluid from arround the baby is taken and cells sent for kanyotyping.Early results with Fish in 48 hours and entire results in 2-3 weeks.Risk of miscarriage around 0.5 -1 %.
I will briefly inform her that if test confirm Down\'s syndrome then she should know that 20% of children will die before age of 1 year while 45% reach the age og 60 years.There will be mental retardation with IQ around 50.Although Down\'s Syndrome babies can walk,talk and have self care skills but indepence is rare.Baby can have congenital heart defects,gastri intestinal defects and later age can develop Alzhimer\'s disease.Her intention of continuing pregnancy or wishes for termination should be respected after full counselling.In situation where she wants to continue this pregnancy risk of Intra uterine growth retardation oligohydrammios still birth will increase.She will need serial ultrasound Doppler groqth scans for fetal growth and well being.Multi Disciplinary approach with early involvement of pediatrician . Aim should be of vaginal delivery with Caessarian section for obstetric reason.I will give her written information for down\'s syndrome to help her making informed decision.I will provide her numbers & address of support group.
Posted by Shilpa G.
a. i would ask history of previous baby with down syndrome, chromosomal abnormality in family, h/o conception with IVF . the background risk according to her age is about 1 in 100. she should be explained that it means that 99 babies are normal but 1 baby is affected. she should be offered further screening methods like free b hcg in her blood which may be elevated in down syndrome and PAPP a levels in blood which may be decreased. the sensitivity of these biochemical tests is 30% and invasive fetal testinf is 5%. she should also be offerred NT scal where the nuchal translucency is measured between 11w3d to 13 w 6 d. then adjusted risk should be assesed depending on the NT measurement , which if normal then the risk of downs reduces than the background risk. the sensitivity of NT scan is 70%. Involvement of geneticist, fetal medicine spesialist may be neded. the advantages of 1 trimester screening should be explaine where she can be reassured early and if aneuploidy detected, then she can opt for termination of pregnancy. If she refuses 1 trimester screening, then biochemical screening ( triple marker) at 15-18 weeks should be offered, sensitivity of this is 60% and invasive testing( amniocentesis) is 5%. Integrated testing where both 1 tri and 2 nd tri screening is done , sensitivity is 90%.
b. if her adjusted risk is 1in 25, she should be counselled if she needs her partner to be present during the counselling, then the request should be respected. The finding means the chance of her baby not being down syndrome is 24 , so she needs further testing to confirm whether her baby has down syndrome which can be done by amniocentesis where the chance of miscarriage is in 1 in 100 but since the risk of down syndrome is more , she should weigh the risks and then decide.if the amniocentesis comes as karyotype trisomy 21, the she should be counselled that the child is affected and further options should be explained, where support group involvement, and if she wants to continue pregnancy , she can do so. the option of termination of pregnancy should also be offered , and the chance of her having a down syndrome baby in subsequent pregnancy which will be increased should be explained. if normal karyothgpre, then s he can be reassured and pregnancy can be continued, but if she declines to do further invasive testing, then implications to be explained and 2 trimester biochemical screening to be offered which along with NT scan + 1 tri PAPPa and free b hcg sensitivity will be 90%
Posted by Mohamed A.
a)
According to her age the risk of having a baby with DS is about 1 in 100.I should ask about history of having a previous baby with Down’s syndrome, the risk of recurrence in a subsequent pregnancy increases to approximately 1 percent above the baseline risk .I should ask if one parent carries a balanced translocation that makes recurrence risk higher.

I will offer her screening tests which includes serum screening and ultrasound screening. These tests can be used in combination or separately. The chance of the fetus having Down\'s syndrome is calculated using software that takes into account maternal age and gestational age and putting into consideration factors that might affect serum screening such as increased maternal weight and insulin dependent diabetes which lower serum markers levels, recent bleeding increases the serum AFP, afro-caribbean women have higher levels of AFP and HCG compared to Caucasians. Also serum markers are unreliable in multiple pregnancies. Also in assisted conception using donor eggs, risk should be calculated using the age of the donor and HCG levels are higher in assisted conception. Screening test is positive if the probability is equal to or greater than the nationally agreed cutoff level which is 1 in 250 in the UK.


I will start with the combined test according to the NICE guidelines which can be performed between 11–14 weeks and involve measuring nuchal translucency and serum HCG and PAPP-A this test can detect up to 85 % of Down’s syndrome with a false positive rate of about 6%. Measuring NT alone can have an 85% detection rate with up to 20% false positive rate.
Further testing can be performed in the second trimester adding the quadruple test by measuring the AFP, HCG, uE3 and inhibin A (the so called integrated test) increases the accuracy with a false positive rate of 1.2% for an 85% detection rate. If measurement of the NT is not possible (because of fetal position or increased maternal weight), she should be offered serum screening (triple or quadruple test) between 15 and 20 weeks these tests have a false positive rates of 9.3% and 6.2% respectively.


b)

According to the screening result, the woman and her partner should be offered proper counseling by a trained staff, ensuring that the woman understands what 1 in 25 means, 24 out of 25 chance of fetus being normal . Counseling should include accurate information about Down’s syndrome ensuring that the woman understands the aetiology of Down’s syndrome and reassure her that it is not due to her diet or life style .The implications of having a baby with Down’s syndrome and the possibilities if IUFD, structural anomalies, learning disabilities and need for long-term care.

I will explain to her the fact that screening tests does not give a definite diagnosis, and I will offer her a diagnostic testing either a chorionic villus sampling or an amniocentesis after explaining each procedure. Both procedures are performed under ultrasound guidance and local anesthesia. CVS may be performed between 10-13 weeks and involves aspiration of placental tissue, using a trans-abdominal or trans-cervical route. With a risk of miscarriage of about 2-3%. CVS allows an earlier diagnosis to be made. Amniocentesis is best performed after completed 14 weeks and involves trans-abdominally aspirating sample of the amniotic fluid and risk of miscarriage is about 1%. Also there is a risk of feto-maternal transfusion so Rh typing is recommended. I should obtain formal consent prior to the procedure, and I will offer her written information.

I will inform her that the results will be available after 72 hours using FISH technique and full karyotype i.e. confirmation and detection of other chromosomal abnormalities rather than Down’s syndrome may take up to 3 weeks. Normal karyotyping is reassuring.

If the results confirms Down’s syndrome I will discuss her attitude to the affected fetus and she have the options of termination of pregnancy or to continue the pregnancy.

If she opts to continue pregnancy or refused invasive testing, she should be offered a detailed anomaly scan at a specialized feto-maternal unit at 18-22 weeks, the findings of anomalies such as cardiac defects or dudenal atresia may alter her decision to continue pregnancy and second trimester TOP should be considered, options include mifipristone, misprostol and oxytocin and intra-cardiac KCL. I will obtain consent for post-mortem fetal karyotype.

If she wants to continue pregnancy despite confirmed Down’s syndrome, her wish should be accepted. She should be offered serial growth scans as there is risk of IUGR. According to the result of the anomaly scan I will counsel the parents regarding place of delivery and the possible need for corrective surgery for the baby. Refer to counsel a specialized neonatologist or a neonatal-pediatric surgeon.

I will refer both partners for genetic counseling for assessment of risk of recurrence, I will explain the need for early prenatal diagnosis in subsequent pregnancies. And I will provide written information and support group contacts.








Posted by SUNDAY A.
Sunday
a)The risk of having a baby affected with Down\'s syndrome would depend on the correct estimation of gestation age- this can be confirmed with an early scan or by the LMP with its limitation, age of the patient- as it is over 35yrs, the patient is in the high risk category. Parity of the patient, previously affected pregnancies and outcome, family history of down\'s syndrome all contirbute to the initial risk assessment.

b) Couselling would centre around giving evidence based advice on the relevant test that can be done to confirm or exclude Down\'s syndrome if the patient so desires. If she declines any investigation and decides to carry on with the pregancy she should be informed of the possible outcome and likelihood of supporting a child with Down\'s syndrome in terms of the emotional, psychological, physical and financial resources that may be involved. She should be given contact address of support group and association that care for patients with Down\'s syndrome for support.
If the patient deires for testing, i would advice her to consider a diagnostic test in the first instance such a Chorionic villus sampling which can be done as from 10 weeks or amniocentesis which can be done as from 14-16 weeks telling her of the risks, time frame for results availability and limitations. I can also offer her fetal blood sampling for Karyotype and fetal DNA analysis from maternal serum- the disadvantage of this is that its costly and not widely available in the UK for now. The patient must have a clear plan of action paraventure the test confirms Down\'s syndrome ie- consideration for termination of pregancy or carrying on with pregnancy.
If she objects to the above diagnostic tests, i can offer her first trimester serum screening combined with nuchal translucency or 2nd trimester screening ( Quadruple test). I would emphasise that these are screeing test with varying degree of sensitivity and specificity. I would also offer her an anomaly scan at 18-20 weeks and a fetal cardiac scan at 24 weeks if she has objected to invasive procedure.
Whatever her preference i would ensure that all the discussion is well documented in her notes. I would also involve her in making an informed choice regarding the pregnancy, encourage the support from her partner and family and a named midwife to reinforce the discusion once she has left the clinic. Information leaflets and contacts of support groups would also be given.
Posted by shagf A.
A. Her risk to have baby with down\'s syndrom at 35yr is 1:350 and risk is 1:100 at age of 40. I will aske her if she have previous baby with down\'s syndrome, history of recurrent misscarge or she have a family history that will increase her risk and may justify the karyotyping for parents as balanced traslocation (Resibrecal & Robertosonin)of one of the parent can lead to 5-10% risk of baby with unbalanced translocation. I will confirm her date and number of preg by ultrasound scan as all avilable screeing test depend on gasation age and multiple preg the screening will be by nucal thickness only(at cut off 3.5mm).
I will offer her screening test according to the local and national guideline, the first trimester 8-14 ws (comined ) test which will calculate risk depend on Nucal thickness, pregenacy spesific plasma protein A, and free B HCG. This test will give her chance to terminate early if required after diagnostic test with CVS, ususally result at single visit so avoid waiting anxity & the detection rate is 85% and false possitive 5%. If not avilable locally I will offer her second trimester screeing test either triple or quadrable (MSAFP,HCG,UE& Inhibin), with 76% detection rate and 5 % false pssitive . the false possitive rate can be affected by increase mother weight, smoking & IDDM. Integrated screening test will reduce the false possitive to 1%, but it will obviate the benifits of early combined test.
B. I would counsel her sympthatically, I will tell her that this risk mean that her personal risk of haveing baby with down sy, will be 1:25 and she still have 24:25 chance of having baby without down sy. This risk is high and need to be confirmed if termination would be option for her.
I will tell her That the avilable diagnostic test either CVS at 11w-13w+6 , or amniocentesis after 15 w, which will require to send her to fetomedicine unit. the CVS will have the advantage of early diagnosis so we can terminate early if required, have 2-3% misscarge rate and small risk of musiasm . It is invasive procdure involve obtaining the placental tissue, it can be done abdominal but ussually vaginally. Amniocentesis will have 1% misscarge rate , small risk of infection , 0.5% risk bloody tap which will requir to repeat it. It involves taken amniotic fluid for either preliminary test using FISH result will be within 48 hr and culture result take 1-2 weeks. The result will diagnsis other anyoploidy trisomy 18 and 13 but will not exclude othe structural or genetic problems. local analgesia will not required she will be like venous puncture and under ultrasound guide. the fetomedicne will counsell her, take the consent , and tell her the local failure rate , who will do it to her and after the test they will give her verbal and written information , 24 hours telephone advice, as she may have mild contraction but if she have leakge bleeding or contraction she should contact hospital.
If result will be negative that will return her to rountine AN care. If results diagnsis Down\'s syndrom, information will be given to her personally with counseller have expertise in disscussing and breaking this news . Information regarding; Down\'s syndrom, which associated with typical dysmorphic features,different degree of mental retadation, structural abnormality such cardiac and have short lifespan. Offer her time and support to make decion regarding either termination or even if she decide to continue pregancy her decion will be respected and she will need support and close ultrasound suirvillance bec it will be associated with high risk of growth restriction , hydrobs and still birth.
Posted by Sameena M.
risk can be assesed by history ,nucal translucency scan,and serum screening .
age,family history of downs syndrome will increase her risk.
increased nucleal translucency ,decreased afp and increased papp increase her risk of downs syndrome.
once the risk is known explain to patient that she has more chances of having a baby without down syndrome.
explain that it is a screening test and not a diagnostic test .
offer her cvs and explain the risks of cvs.
explain that she can have top if she wants and she can carry on with pregnancy and she will be supported in all her decisions.
explain the implications and health effects of downs syndrome
Posted by A H.
A
a)I will enquire about the reason for her concern, whether it is due to her age or if she or a close relative had a baby with Down\'s syndrome. If there is no personal or family history then she will be offered screening.
Her age related risk is approximately 1in 200. Her dates will be confirmed by ultrasound the combined test will be offered. This is done between 11 and 14 weeks gestation and consists of measuring nuchal translucency, and maternal serum levels of Pregnancy associated plasma protein A (PAPP-A) and free beta HCG. If facilities are not available for the combined test, then the quadruple or triple test will be offered. Other screenig tests are the double test and Nuchal translucy determination. The detection rate for these are much lower with a higher false positive rate.
If there is a positive family or personal history of having a baby with Down\'s syndrome, her previous notes will be perused to see if the cause of the syndrome was determined by genetic testing. If the history is one of non-disjunction Down\'s syndrome, her risk will be same as the background risk for her age. If there is a history of translocation Down\'s in the patient she will have a 15% risk of having a baby with Down\'s syndrome. If the partner is positive, the risk is 1%. She will be counseled and will be offered invasive testing.Information leaflets will be given to explain what Down\'s syndrome is and methods of screening.

b)Counselling will be done by trained counsellors in a dedicated setting where there is privacy. Enough time without undue interruption will be spent with the patient. She will be informed that she has a high risk oh having a baby with Down\'s syndrome and a diagnostic test must be done to find out if the baby is affected.This can be either by chorionic villus sampling at 11 to 13 weeks or amniocentesis from 15 weeks onward
Amniocentesis involves removal of a small amount of amniotic fluid under direct ultrasound guidance by a suitably trained person. It is associated with a procedure related pregnancy loss rate of 1%. If local figures are available she will be informed about this. She will be told that it takes about 2 to 3 weeks to obtain the results. Ther is also a risk of culture failure of 1%or serious infection of less than .1 %,
Chorionic villus sampling (CVS) requires a more specially trained personnel, and involves taking a small sample of the placenta for testing. She will be told that results are obtained within a few days, but the risk of foetal loss is about 3% greater than for amniocentesis. CVS can be done by either the trans-abdominal route or the transcervical route, both under direct ultrasound guidance.Both routes carry the same foetal loss risk. Other risks associated with CVS include placental mosaicism and infection. Informed consent will be taken and the patient will be given information leaflets, and if necessary a next appointment to address her concerns and answer questions before testing..
Further management will depend on the results obtained. If a negative result is obtained she will be appropriately counselled and followed in the antenatal clinic. If the results show an affected foetus she will be counselled on prognosis for the baby which includes severe mental retardation,risk of congenital heart diseae mainly ASD and VSD, leukaemia, thyroid disease and a shrtened life-span of about 45 to 55 years. She will also be told that the baby will not be capable of indepent living even as an adult.
She will de given the option of termination of the pregnancy(TOP) or expectant management.Methods of TOP will be discussed as well as the pros and cons of each.
If she opts to carry on with the pregnancy,plans for obstetric intevention due to a fetal indication will be discussed and clearly documented in the notes. She wil be given written information on caring for her baby as well as contact numbers for support groups. The recurrence risk will be discussed and she will be advised to book early in a subsequent pregnancy. She will be reminded that there is no cure for Down\'s syndrome nor is there any prophlactic measures that can be taken.
Posted by GHADA AHMAD  M.
A.
I would ask about family history of Down,s syndrome. I will assure here the risk of having baby with down\'s syndrome is 1:100 for here age. as she is 10 weeks of gestation, I will ask for her nuchal translucency screening. If it is normal I will reassure here.
B.
considering nuchal translucency is abnormal, so I will offer here more diagnostic tests. I would explain here Chorionic villus sampling that can be done between 10- 13 weeks and explain that it is a diagnotic test. I will explain the nature of the test which is needle biopsy from the placenta under US control. She must Know the risk of miscarriage 1-2% and result of the test come after one week. the alternative test is amniocentesis which can be done after 15 copmleted weeks. It is needle aspiration of the flued around the fetus. I will also explain the risk of miscariage 0.5 - 1 % and the results of the test will be available after 3 weeks. there other screening tests like triple test but the sensetivity of it is 68%. If the diagnostic test is abnormal I will descuss here regarding termination of pregnancy. If normal I will reassure here regarding Down\'s syndrome. I will descuss here regarging other causes for abnormal nuchal transluceny like cardiac abnormalities
Posted by PAUL A.
RnRn

A.
Initial assessment the word INITIAL did not appear in the question by means of history taking; positive family history or previous children with Down’s or perhaps unbalanced translocation in her or her partner ?? what does this do to her risk? . Vast majority (>95%) of cases though is “the-novo” mutation is Down’s syndrome caused by a mutation?? (-1) .
Her background risk for age is around 1:40 ?? at 10 weeks or at term? , but can more precisely estimated by doing serum testing for beta-HCG, AFP & E2 do you measure these in the first trimester? in 1st and 2nd trimester and scan for nuchal translucency around 12 weeks. Based on these findings risk assessment is made with correction for maternal age. With a cut-off of 1:250, this combination of test will identify 83% of cases with 6% false negatives for test done in first and second trimester? DO YOU MEAN FALSE POSITIVE OR FALSE NEGATIVE? if done in 1st trimester only, 1.2% if combined 1st and 2nd trimester (1) . If risk above the threshold, it is justified to offer chorion-villi biopsy you were asked to assess her risk = screening, NOT diagnostic tests around 13 weeks, or amnion-punction from earliest 16-17 weeks onwards, as risk for iatrogenic pregnancy loss is respectively 0.5-1% and 0.5%. If she is not keen for CVB or AP, than she can be scanned at 20 weeks to look for soft markers, though this will pick up less cases and is not very specific. your knowledge of Down’s syndrome screening needs to improve – see notes

B.
She must be told this doesn’t mean her unborn child has downs, but rather that the risk for this is higher than expected based on her age. She must be fully aware what Down’s means (1) in terms of having a child with mental restricted capacity, requiring life-long care, shortened life-span and with comorbidities such as atrium-septum defect being common. It is good to discuss beforehand what she’d like to do if test turns out positive for Down’s; termination only possible up to 24 weeks see Clause E of the Abortion Act – to gestation age limit , in second trimester termination by means of Mifepristone and cervagem as compared to late termination after 20 weeks ?? is 20 weeks not second trimester? . She must take into account that a number of pregnancies with down would miscarry anyway, an that spontaneous miscarriage may be emotionally less taxing than having to go for pregnancy termination. She must be told that earliest available test is chorion villi biopsy (1) around 13 weeks, with documented limb defects if too early why mention it if you are not going to do it too early? and iatrogenic pregnancy loss in 0.5-1% (1) , if transcervical up to 2%. Amnion punction amniocentesis is only possible from 16 weeks onwards, with iatrogenic pregnancy loss 0.5% (1) , often due to infection or leaking liquor. She must know about possibility of false negatives or positives, such as in mosaicism. Karyotyping by means of FISH will yield results as fast as within 72 hours (1) and can identify numbers of chromosomes only, such as 13, 18 and 21. PCR will take longer ?? why should PCR take longer? Full karyotype will take longer , but gives additional information about the form of chromosome. I will give her further written information to read up.

Your level of factual knowledge needs to improve
Posted by PAUL A.
it is important to begin by taking a history of an affected individual in the family what is her age-related risk and how is this affected by family Hx? .She should be explained about screning tests which are not diagnostic but suggest an increased risk of trisomies and necessitate further invasive tests which are diagnostic.She should be offered Integrated test (detection rate of 90%and a false positive rate of 2.8% ) (1) which includes NT and PAPP_A at 10 weeks and free b-hcg,AFP,ue3 at 14-20 weeks.If however the estimation of NT is difficult due to obesity or abnormal fetal position then serum integrated test can be offered including PAPP-A at 10 weeks and free b-hcg,AFP,ue3 at 14-20 weeks with a detection rate of 85% and a false positive rate of 2.7% (1) .The results of these tests have to be waited for till second trimester when the test starts in first trimester prolonging the agony of the lady.Also it delays the decision to terminate and affected pregnancy if so desired by the lady to the second trimester.Thus,if first trimester screening is desired combined test(detection rate 85%with 6.1%false positive rate) includind NT,Free b-hcg,PAPP-A at 10weeks can be offered (1) so if you were the woman, will you have first trimester screening and run a higher risk of losing your baby because of unnecessary invasive testing or wait till second trimester and have integrated test with a much lower false positive rate? .However if she deisres a test in the second trimester then quadruple test(detection rate of 85%with false positive 6.2%)including AFP,b-Hcg,ue3,inhibin A and also the triple test(85%detection rate with false positive of 9.3%)including AFP,b-hcg,ue3 at 14-20 weeks can be offered.
b)It is essential to sympathetically (1) explain the increased risk to the couple and the need to confirm it with invasive tests.She should be offered support as this could be devastating to her.She should be explained the association of Down\'s syndrome with cardiac malformations(ASD),GI anomalies(Duodenal atresia),renal anomalies other than subnormal intelligence and increased risk of developing leukaemia,thyroid disorder,alzheimer\'s disease and epilepsy (1) .It is thus essential to confirm this disorder by invasive tests like CVS,Amniocentesis (1) ,Fetal blood sampling.CVS can be done transabdominally at 11 weeks and has a 1-2%risk of miscarriage as also 1%risk of placenatl mosaicism that needs to be confirmed by amniocentesis.Amniocentesis can be done at 15-20weeks under ultrasound guidance transabdominally and has a 0.5-1% risk of miscarriage procedure-related or above background as also increased risk of infection.fetal blood sampling is done at 18-20 weeks and is not preferred at this indication due to high risk of side effects like bleeding,cord haematomas,fetal bradycardias,intrauterine deaths.Use os FISh and fluoroscent labelled probes enables test results in 3 working days (1) .CVS has the advantage of earlier diagnosis and earlier termination if pergnancy is affected.If results of invasive testing are positive then the couple needs further counselling and termination should be offered discuss options including TOP .If desired it could be done medically or surgically.If continuation of pregnancy is desired then they should be referred for genetic counselling and paediatric counsultation.They should be asked about no monitoring in labour to avoid cesarean section and no active resuscitation of the newborn.Also neonatologist to attend delivery.They should be informed about support groups (1) like which one?.
Posted by PAUL A.
PART A
As she is 39yrs old her age related risk is about 1:150 at term (1) EXCELLENT – risk should be quoted in relation to gestation age .95% Down syndrome are due to trisomy21 and only 4% are due to translocation involving chromosome21.Iwill enquire whether she or her partner is having Downs syndrome or are known to have chromosomal translocations. Any previous pregnancy with Downs baby and family history,because any of these factors increases likelihood of Downs Syndrome previous baby then risk = 1% + background risk unless translocation .Further risk assessment will be based on screening test results.A range of screening test are available.I will offer combined test as it is done early between 11-13 weeks and involve nuchal translucency,PAPP-A and free BHCG with 85% detection rate but high(6%)false positive rate (1) .Its advantage is that it is a single point test.Other tests like Integrated test(NT plus PAPP-A at 10wks and AFP,UE3,freeBHCG and inhibin A at 14-20wks)is most effective test with 85% detection rate for only 1.2%false positive rate (1) but it involves both first and second trimester screening and delay in further management.Other test like Quadruple test,triple test and double test are 2nd trimester screening test with high false positive rate.
PART B
I will ensure that test result is accurate by ascertaining her gestational age.As test results are likely to create anxiety,my approach would be sensitive,supportive and empathic (1) .I will explain to her that screening only identifies whether a particular baby is at risk of Down Syndrom, but it does not provide definitive diagnosis (1) .There is only 1 chance out of 25 of having downs baby. For its confirmation diagnostic tests are available which are more invasive, expensive and are associated with complications. I will explain that there is a spectrum of Downs Syndrome abnormalities (1) including risk of miscarriage, IUD, structural abnormalities like congenital cardiac defects (AV Canal), GIT defects(like duodenal atresia),limb defects,congenital cataract and urinary tract defects. On birth appearance of the baby is like having slanting palpebral fissuras, epicanthic folds, open mouth with protruding toung. There will be learning disabilities and long term risk of thyroid disorder, leukaemia, Alzheimer’s disease and epilepsy. Life expectancy is between 50-55 years, so long term care is required. But all babies with Downs Syndrome do not have all of these features, they vary in it ranging from mild to severe. I will offer diagnostic test like chorionic villus sampling (1) . It is performed after 10 weeks by transabdominal or transcervical route with early report within 48hrs by FISH/PCR technique but culture results within 2-3wks (1) . There is a risk of miscarriage 1-2% above background risk (1) , placental mosaicism 1%, infection and rhesus immunisation.It provides opportunity for easy and early termination of pregnancy which is less traumatic both psychologically and procedure related. Other options is amniocentesis performed after 15 weeks of gestation transabdominally. It is associated with 0.5 to 1% risk of miscarriage above background risk, culture failure 0.5%, infection and rhesusisoammunisation (1) . If the test results are negative I will reassure the patient and rest of the pregnancy will be managed as a routine (1) . If the test results are positive I will explore the patient’s attitude towards pregnancy whether they want to continue or terminate it (1) you may do this before offering invasive testing .If they are willing for termination of pregnancy I will discuss different methods of termination (medical/surgical) with benefits and risks explanation. If they want to continue the pregnancy, I will respect their wishes and provide support in their decision. I will provide the information about Downs Syndrome parenting, contact details of support groups like Down’s Syndrome association and Downs’ Syndrom medical Interest Group (1) and written information of above detail.I will offer detail anomaly scan at 20wks to look for structural anomalies (1) like cardiac,GIT, other defects,and Soft markers like choroid plexus cyst, echogenic bowl associated with down syndrome. It will help in further counseling of the parents and they can review their decision about pregnancy. In case of cardiac and GIT defects serial growth scans and liquor volume will be done after 28 weeks of gestation for early detection of complications how will you respond to these scans? If you have a fetus with Downs and a severe cardiac defect and you detect severe IUGR at 28 weeks, will you deliver by CS? If not, why do the scan? . I will involve neonatologist, paediatrician and pediatric surgeon to discuss the fetal/neonatal prognosis with parents and postnatal management. I will also discuss the recurrence risk and referral to the geneticist for genetic counselling. I will discuss the place,mode of delivery and criteria for intrapartum intervention for fetal reason with parents. Aim is for vaginal delivery. Neonatologist should be present a the time of delivery for the detailed assessment of the baby. In the post partum I will discuss contraception before discharge and plan for subsequent pregnancy.

eriod I will discuss the contraception before discharge and the plan for subsequent pregnancy

Good answer
Posted by PAUL A.
her risk of down syndrome can be assessed base on her age what is the risk at 39? ,first trimester bichmical screening ,nuchal transluscency measurement between 10-13 weeks gestation or second trimester biochmical method.done alone these all methods have low sensitivity what is low? 10%?? with high false positive rate.combining ist trimester biochmical screening with nuchal transluscency gives better sensitivity.further combining it with 2nd trmester quadruple test and age related risk improves it further with low false positive rate what is the sensitivity / false positive rate? thus reducing the number which will need invasive testing and pscychological morbidity.
the result of 1;25 is going to the patient very worried and likely to put her in exreme anxiety.so the result need to be conveyed to her in a sympathetic (1) way by a person who is experienced to do so.i will counsel her that still she has more chances of having a baby without down syndrome.there are diagnostic test available which will help us know with more certanity about the baby having down syndrome. i will counsell her about invasive techniques of prenatal diagnosis that is amniocentesis and CVS (1) .i will inform her that procedure related miscarriage rate is 1% AND 2% respectively (1) .the other noninvasive tehnique is the use of free DNA in maternal circulation .the advantage as the non invasive nature of the test thereby limiting morbity .i will discuss with her the time after which the result will be available when will that be? and about her plans in case the baby is diagnosed with trisomy 21.further mangement will be dependent on the result of diagnostic testing.if patint chooses to terminate the pregnancy or plans to continue in both cases she will be supported in her decision. miscarriage arranged in first case ? meaning with followup visit and a support group.if she chooses to continue pregnancy she will need to understand the special needs so liasion with neonatologist for the rest of pregnancy will be done.infomation about the support group will be given (1) do you know any examples??

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Posted by GHADA AHMAD  M.
A)
According to her age the risk of having a baby with DS is about 1 in 100 at term . I should ask about history of having a previous baby with Down’s syndrome, the risk of recurrence in a subsequent pregnancy increases to approximately 1 percent above the baseline risk . I will start with the combined test which can be performed between 10 completed weeks gestation and involve measuring nuchal translucency (NT) and serum HCG and PAPP-A this test can detect up to 85 % of Down’s syndrome with a false positive rate of about 6% . Further testing can be performed in the second trimester (14 -20 weeks) , the triple test (AFP, HCG, uE3) with 9% false positive and 85% detection rate the quadruple test by measuring the AFP, HCG, uE3 and inhibin A (the so called integrated test) increases the accuracy with a false positive rate of 1.7% for an 85% detection rate . The integrated test which combined first and second trimester markers (NT+ PAPP-A at 10 weeks combined with quadruple test) with a false positive rate of 1.2% for an 85% detection rate.

B)
I will explain her implications of having a baby with Down’s syndrome and the possibilities if IUFD, structural anomalies, learning disabilities and need for long-term care. I will explain to her the fact that screening tests does not give a definite diagnosis , and I will offer her a diagnostic testing either a chorionic villus sampling or an amniocentesis . Discussion of the nature of both techniques and possible risks making sure that she is completely understand. A further appointment and hospital contact details to be offered. Normal karyotyping is reassuring. If the results confirms Down’s syndrome I will discuss her attitude to the affected fetus and she have the options of termination of pregnancy or to continue the pregnancy. If she opts to continue pregnancy or refused invasive testing, she should be offered a detailed anomaly scan at a specialized feto-maternal unit at 18-22 weeks. I will obtain consent for post-mortem fetal karyotype. If she opt for termination of pregnancy I will discuss the her about the mode of termination either surgical or medical. I will discuss the possible risk and benefit for termination and anaesthesia.