a)I would adopt a sensitive approach to the patient during the consultation as suspected small for gestational age is associated with high maternal anxiety.Detailed history is asked about symptoms such as headache ,visual disturbances and epigastric pain which suggests preeclampsia.She is asked about any abdominal pain, recurrent episodes of vaginal bleeding and any reduced fetal movements to identify concealed abruption. History of infections such asToxoplasmosis,Rubella,cytomegalovirus and malaria and in the antenatal period is elicited as associated with IUGR.Social history includes any history of smoking,excess alcohol and caffeine intake,domestic violence and poor nutrition.Occupational history includes kind of job and any stress at work.Family history is asked about low birth weight babies as constituitional SGA fetus accounts for 50% of SGA fetus. Financial background,support from the partner and other family members should be elicited.Ethnic origin of the patient should be noted as babies of mothers born to Asian, middleeast and African origin can be a constituitional SGA fetus .
Examination
I would check BMI as inadequate maternal weight gain can lead to SGA fetus.BP and urine protein are checked to identify preeclampsia.Abdominal examination is done to measure symphysiofundal height and measurement should be plotted in the customised chart.Fetal Heart should be auscultated and documented.Serial symphysio fundal height measurement should be done in suspected SGA fetus.
Investigations include CTG examination to detect any fetal heart abnormalities.The presence of normal baseline, variability,presence of accelerations and absent decelerations is classified as a normal CTG.Ultrasound examination is done to check fetal growth by measuring the abdominal circumference and estimated fetal weight,amniotic fluid volume and umbilical artery doppler.Estimated fetal weight by ultrasound examination has got only +/- 20 % accuracy,but it is the only available investigation to estimate fetal weight.Estimated fetal weight assessment uses customised chart to improve accuracy.Amniotic fluid volume should be based on single deepest vertical pocket.Biophysical profile should not be used for surveillance in SGA fetus.
b)Estimated fetal weight/Abdominal circumference less than 10th centile is defined as small for gestational age fetus.Therefore this baby is classified as small for gestational age.
Options for monitoring SGA fetus include use of growth scan ,umbilical artery doppler,ductus venosus doppler, middle cerebral artery doppler and computerised CTG.
In high risk populations use of umbilical artery doppler has been shown to reduce perinatal morbidity and mortality.Ductus venosus doppler has got moderate predictive value of adverse neonatal outcome and should be used in the preterm SGA fetus with abnormal umbilical artery doppler to time delivery.In preterm SGA fetus,MCA Doppler has limited accuracy in predicting adverse neonatal outcome.
In term SGA fetus,an abnormal middle cerebral artery has moderate predictive value for acidosis at birth.
If normal dopplers is confirmed ,can repeat growth scan every 3 weeks and umbilical artery dopplers every 2 weeks.Delivery can be planned by 37 weeks or after 34 weeks if static growth over 3 weeks or MCA Doppler PI<5th centile.
If Pulsatility Index/Resistance Index >2SD,but end diastolic velocity present ,growth scan needs to be repeated every week to check for abdominal circumference and estimated fetal weight.Umbilical artery dopplers needs to repeated twice weekly and delivery can be planned by 37 weeks or after 34 weeks if static growth over 3-4 weeks.
If absent/reversed end diastolic velocity present, patient should be admitted and growth scan needs to be repeated weekly and umbilical artery Doppler and ductus venosus Doppler daily.Also computerised CTG should be done daily. Steroids can be given and deliver by 32 weeks or between 30-32 weeks if ductus venosus Doppler /Computerised CTG abnormal.Even if ductus venosus doppler is normal delivery can be planned before 32 weeks.
c)
If absent/reversed end diastolic volume is detected in the dopplers ,steroids should be given.Corticosteroids reduces the risk of RDS,neonatal death and intraventricular haemorrhage.Check presentation of the baby as malpresentation are common in preterm babies and transverse presentation can cause potentially difficult caesarean section.
Inform special care baby unit and arrange discussion by neonatalogists with the parents about the possible outcome.If adequate neonatal facilities are not available ,consider in-uterotransfer if time permits.Otherwise exutero transfer is indicated.Life style advises to improve nutrition if inadequate maternal weight gain,quit smoking and reduce alcohol intake would improve neonatal outcome.Early detection and treatment of preeclampsia if present is associated with reduced perinatal morbidity and mortality.
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