Infant outcome after active management of early‐onset fetal growth restriction with absent or reversed umbilical artery blood flow

OBJECTIVE: To describe the short‐ and long‐term outcomes of infants with early‐onset fetal growth restriction (FGR) and umbilical artery absent or reversed end‐diastolic flow (AREDF), delivered before 30 weeks' gestation and managed proactively. METHODS: This was a retrospective cohort study of fetuses delivered for fetal indication before 30 completed weeks' gestation that had early‐onset FGR (defined as estimated fetal weight more than 2 SD below the mean) with AREDF in the umbilical artery (FGR group), at the level‐3 perinatal unit in Lund, Sweden, between 1998 and 2015. Perinatal outcome and neurodevelopment at ≥ 2 years of age in surviving infants were compared with those of a group of infants without small‐for‐gestational‐age birth weight or any known fetal Doppler changes delivered before 30 weeks in Lund during the corresponding time period (non‐FGR group). In the FGR group, the main indication for delivery was the Doppler finding of AREDF in the umbilical artery. RESULTS: There were 139 fetuses (of which 26% were a twin/triplet) in the FGR group and 946 fetuses (of which 28% were a twin/triplet) in the non‐FGR group. The FGR infants had a median birth weight of 630 g (range, 340–1165 g) and gestational age at birth of 187 days (range, 164–209 days), as compared with 950 g (range, 470–2194 g) and 185 days (range, 154–209 days), respectively, in the non‐FGR group. The rate of fetal mortality did not differ between the two groups (5.0% and 5.4% in the FGR and non‐FGR groups, respectively). All seven intrauterine deaths in the FGR group occurred before 26 weeks' gestation. In the FGR group compared with the non‐FGR group, severe intraventricular hemorrhage was less frequent and bronchopulmonary dysplasia and septicemia were more frequent (P = 0.008, P < 0.001 and P = 0.017, respectively). In the FGR group, the survival rate at 2 years (83% of liveborn infants) and the rate of cerebral palsy (7%) did not differ significantly from those in the non‐FGR group (82% and 8%, respectively). The rate of survival without neurodevelopmental impairment was higher in the non‐FGR group (83%) than in the FGR group (62%) (P < 0.001), as well as in infants in the FGR group delivered at or after 26 weeks (72%) compared with those delivered before 26 weeks (40%) (P = 0.003). Within the FGR group, outcomes were similar between twins and singletons and, in those who survived beyond 2 years, outcomes were similar between fetuses with absent and those with reversed end‐diastolic flow in the umbilical artery. CONCLUSIONS: Infants delivered very preterm after severe FGR with AREDF in the umbilical artery had a similar rate of survival as did non‐FGR infants of corresponding gestational age; however, they were at higher risk of neurodevelopmental impairment, the risk being most pronounced following birth before 26 weeks. Gestational age remains an important factor associated with the prognosis of early‐onset FGR; nevertheless, the present results support the hypothesis, which should be tested prospectively, that fetuses with early‐onset FGR and umbilical artery AREDF may benefit from early intervention rather than expectant management, and that umbilical artery Doppler findings could be incorporated into clinical protocols for cases very early in gestation. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.