849 Optimal time of delivery in the setting of fetal growth restriction at the 3rd percentile

Abstract

The SMFM recently published guidance regarding delivery timing for fetal growth restriction (FGR) that differed for pregnancies where the estimated fetal weight (EFW) was at the 3rd centile or below. The purpose of this study was to determine the optimal timing of delivery in pregnancies complicated by FGR at the 3rd centile or less diagnosed at 34 weeks gestational age (GA) in the setting of normal fetal vascular Doppler assessment. A decision-analytic model was created using TreeAge software to determine the optimal GA of delivery in the theoretical cohort of 10,000 cases of singleton 3rd centile FGR diagnosed via ultrasound at 34 weeks. The model options ranged from delivery at 34 weeks up to expectant management until 39 weeks’ gestation. Outcomes included stillbirth, neonatal death (NND), and cerebral palsy (CP). In addition, quality-adjusted life years (QALY) were estimated, accounting for both maternal and neonatal utilities. All probabilities were derived from the literature. Delivery at 38 weeks would prevent 5 cases of neonatal death and 24 cases of cerebral palsy as compared to delivery at 37 weeks, while waiting until 39 weeks would result in 19 more stillbirths (Table 1). Overall, the model showed that optimal GA for delivery of 3rd centile FGR was 38 weeks, which maximized total QALYs. Sensitivity analysis revealed that expectant management until 38 weeks was the optimal delivery strategy until the risk of stillbirth in third percentile IUGR fetuses increased by more than 19.7%, when delivery at 36 weeks was optimal. Weighing the risks of prematurity against the outcomes of stillbirth, NND, and CP, the optimal GA to deliver 3rd centile FGR diagnosed at 34 weeks with normal Doppler findings is 38 weeks. However, there are tradeoffs between stillbirth and neonatal short- and long-term outcomes and these findings can be used to counsel regarding a range of clinical management approaches in a shared medical decision-making approach to care.View Large Image Figure ViewerDownload Hi-res image Download (PPT)