Severe Fetal Growth Restriction

Severe fetal growth restriction is an estimated fetal weight or abdominal circumference below the 3rd centile, or any growth restriction with absent or reversed end diastolic flow in the umbilical artery. It results from severe placental failure or from early fetal insults. It carries a high risk of stillbirth and neonatal death, and needs a unit with neonatal intensive care.

• Risk factors: severe preeclampsia, antiphospholipid syndrome, chronic kidney disease, congenital infection, chromosomal disease, previous severe growth restriction.
• Doppler stage decides delivery timing.
• Counselling is needed on outcomes before 26 weeks.

Fundal height is far below dates, fetal movements are reduced and liquor is scanty. Many women have hypertension, proteinuria or severe preeclampsia.

• Marked lag in fundal height.
• Oligohydramnios.
• Differential diagnosis: wrong dates, symmetrical growth restriction, congenital infection, chromosomal abnormality, fetal anomaly, severe preeclampsia without growth restriction.
• Complications: stillbirth, fetal acidosis, extreme prematurity, intraventricular haemorrhage, necrotising enterocolitis, hypoglycaemia, polycythaemia, neonatal death, cerebral palsy.

The approach is ultrasound staging with cardiotocography.

• Ultrasound: estimated fetal weight or abdominal circumference below the 3rd centile; umbilical artery pulsatility index above the 95th centile, absent or reversed end diastolic flow; middle cerebral artery pulsatility index; ductus venosus Doppler; deepest pocket below 2 cm.
• Cardiotocography daily; computerised short term variation below 3.5 ms before 32 weeks or below 4.5 ms after 32 weeks where available.
• Maternal: blood pressure, urine protein to creatinine ratio, full blood count, creatinine, liver enzymes, antiphospholipid antibodies, syphilis, HIV, malaria.
• Amniocentesis for karyotype and cytomegalovirus PCR where an anomaly or symmetrical growth is found.

The principle is admission to a facility with neonatal intensive care, steroid and magnesium cover and delivery at the Doppler stage.

• Supportive: admit; left lateral rest; cardiotocography once or twice daily; Dopplers twice weekly; keep neonatal unit informed; blood group and cross-match; counselling and consent.
• Pharmacological: betamethasone 12 mg IM twice, 24 hours apart, from 24 weeks to 34 weeks and 6 days when delivery is likely within 7 days; magnesium sulphate 4 g IV over 20 minutes then 1 g per hour until delivery for 24 hours at most before 32 weeks (stop for absent patellar reflexes, respiratory rate below 12 per minute or urine below 30 mL per hour, with calcium gluconate 1 g IV over 10 minutes for toxicity); labetalol 200 mg oral every 8 to 12 hours (maximum 2.4 g daily) or nifedipine modified release 30 to 60 mg oral once daily (maximum 120 mg) for hypertension; oxytocin 10 IU IM at birth.
• Procedures: caesarean section at 30 to 32 weeks for reversed end diastolic flow and at 34 weeks for absent flow, and at once for abnormal ductus venosus, pathological cardiotocography or severe preeclampsia; induction at 37 weeks if Dopplers stay normal.
• Special groups: newborns need warmth, kangaroo mother care, feeding within 30 minutes, haematocrit (partial exchange if above 65 percent) and glucose checks at 2 hours, with glucose below 2.6 mmol/L treated by dextrose 10 percent 2 mL/kg IV over 10 minutes then 80 mL/kg per day.
• Red flags: reversed end diastolic flow, abnormal ductus venosus, pathological cardiotocography, absent fetal movements, severe preeclampsia, bleeding.
• Follow-up: daily cardiotocography; Doppler twice weekly; neonatal intensive care follow-up with developmental review at 2 years.