OB/GYN
A pregnant woman at 38 weeks of gestation is diagnosed with intrauterine growth restriction (IUGR).
Ultrasound assessment shows an amniotic fluid index (AFI) of 3 cm. Which of the following is the most appropriate next step in management?
Explanation
Core Concept: Intrauterine Growth Restriction (IUGR) complicated by oligohydramnios (AFI < 5 cm) at term indicates severe uteroplacental insufficiency. The intrauterine environment is now more hazardous than the neonatal intensive care unit.
Clinical Presentation:
- Fundal height lagging behind gestational age, decreased fetal movements.
- Complications: Fetal hypoxia, meconium aspiration, stillbirth, and neonatal hypoglycemia/hypothermia.
Diagnosis:
- First-line and Gold Standard: Obstetric ultrasound showing an estimated fetal weight < 10th percentile, oligohydramnios, and potentially abnormal umbilical artery Doppler studies (e.g., absent or reversed end-diastolic flow).
Management:
- Acute management: At 38 weeks (early term), fetal lungs are mature. Immediate delivery is indicated to prevent fetal demise.
- Long-term/definitive: If the fetal heart rate tracing is reassuring and there are no other contraindications to vaginal delivery, induction of labor is the most appropriate next step. Continuous fetal monitoring during labor is mandatory, as these fetuses have poor reserve and are at high risk for intrapartum distress, which would necessitate an emergency Cesarean section.