What is the management approach for intrauterine growth restriction (IUGR) with abnormal Doppler changes?

Management of IUGR with Abnormal Doppler Changes

The management of intrauterine growth restriction (IUGR) with abnormal Doppler changes should follow a structured protocol with umbilical artery Doppler assessment as the cornerstone of surveillance, with timing of delivery based on the severity of Doppler abnormalities and gestational age to reduce perinatal mortality and morbidity. 1

Surveillance Protocol

• Weekly umbilical artery Doppler assessment should be performed as the primary surveillance tool for IUGR fetuses, as its use is associated with a significant decrease in perinatal mortality 2, 1
• Increase Doppler surveillance to 2-3 times per week when IUGR is complicated by oligohydramnios, or absent or reversed umbilical artery end-diastolic flow 2
• Combine Doppler assessment with traditional fetal surveillance methods:
  • Twice weekly nonstress testing with weekly amniotic fluid evaluation, or
  • Weekly biophysical profile testing 2
• The combination of ultrasound and cardiotographic surveillance techniques has been shown to improve outcomes for IUGR fetuses 2
• Centers with experience in venous Doppler may utilize ductus venosus and umbilical venous Doppler studies, as abnormalities in these vessels indicate significantly increased risk for stillbirth 2

Timing of Delivery Based on Doppler Findings

• For normal umbilical artery Doppler: Consider delivery at 38-39 weeks of gestation 2, 1
• For decreased diastolic flow: Consider delivery at >37 weeks of gestation 2, 1
• For absent end-diastolic flow: Consider delivery at >34 weeks of gestation 2, 1
• For reversed end-diastolic flow: Consider delivery at >32 weeks of gestation 2, 1

Additional Interventions

• Hospitalization: Consider admission when fetal testing more than 3 times per week is deemed necessary, particularly with absent or reversed end-diastolic flow 2
• Antenatal corticosteroids: Administer when absent or reversed umbilical artery end-diastolic flow is noted at less than 34 weeks 2, 1
  • Close observation for 48-72 hours after corticosteroid administration is reasonable, as there may be transient return of end-diastolic flow in about two-thirds of cases 1
• Magnesium sulfate: Consider for neuroprotection in pregnancies less than 32 weeks of gestation 1

Special Considerations

• In very early IUGR (e.g., at 25 weeks) with absent or reversed end-diastolic flow, aggressive obstetrical interventions may be deferred until a later gestational age given the poor prognosis for survival 2
• The single most important prognostic factor in preterm fetuses with growth restriction is the gestational age at delivery, with an increase of 1%-2% in intact survival for every additional day spent in utero up until 32 weeks of gestation 1
• For pregnancies with IUGR complicated by absent or reversed end-diastolic velocity, cesarean delivery should be considered based on the entire clinical scenario 1
• Monitor for development of hypertensive disorders, as maternal hypertension is present in up to 70% of early-onset IUGR cases at delivery 1

Prognostic Value of Doppler Studies

• Using the combination of arterial and venous Doppler testing can identify the majority of fetuses with acidemia (sensitivity 70-90% and specificity 70-80%) 2
• The sequence of arterial and venous Doppler findings is mostly limited to the preterm idiopathic IUGR fetus and has not been well documented in gestations at ≥34 weeks 2
• Abnormal ductus venosus and umbilical venous Doppler studies indicate a dramatically increased risk for stillbirth compared to when only the umbilical and middle cerebral artery Doppler studies are abnormal 2

Common Pitfalls and Caveats

• Avoid delaying necessary intervention in cases with severely abnormal Doppler findings, as the risk of fetal demise increases significantly with reversed end-diastolic flow 2, 1
• Be cautious with corticosteroid administration in severe IUGR cases, as there may be transiently increased physiologic and metabolic demands; close observation for 48-72 hours is recommended 2
• Remember that management protocols for IUGR vary between centers, with most controversy surrounding early-onset IUGR (before 32 weeks) 3
• Don't rely solely on umbilical artery Doppler; the combination with other surveillance methods provides better outcomes 2, 1