(1006) Is Forewarned Forearmed? Pregnancy Outcomes in Early-Onset Fetal Growth Restriction

Early-onset fetal growth restriction (EOFGR) is associated with significant perinatal morbidity and mortality. Our aim was to determine perinatal and infant outcomes of EOFGR, and to evaluate for presence of antenatal predictors of these adverse outcomes.

Study Design:

A retrospective cohort study was carried out from July 2016 to June 2022 of singleton pregnancies with uteroplacental EOFGR diagnosed prior to 32 weeks’ gestation, per Delphi consensus definition, at a tertiary institution with over 8,000 deliveries per year. Genetic, structural or infectious causes were excluded, along with preterm pre-labour rupture of membranes. Adverse outcome was defined as either perinatal mortality (intrauterine fetal demise or neonatal death) or composite neonatal morbidity (outlined in figure 1).

Results:

622 cases of EOFGR were diagnosed during the study period, of which 55% (341/622) were uteroplacental in origin. There was a 95% livebirth rate (325/341), and no terminations of pregnancy. There were 16 intrauterine fetal deaths (7.8%, 16/341) and 11 neonatal deaths (3.2%, 11/341), all occurring in cases diagnosed prior to 28 weeks’ gestation. Adverse outcomes of this cohort are described in figure 1. Table 1 correlates presence or absence of adverse outcome with maternal demographics, ultrasound characteristics and pregnancy outcomes. Unsurprisingly, earlier gestation and lower birthweight at delivery were associated with worse perinatal outcome, along with earlier gestation at diagnosis.

Conclusion:

Reassuringly, there was a high livebirth rate in our cohort, however almost one in four pregnancies experienced an adverse outcome. Maternal demographics such as obesity, assisted reproductive technology, and chronic hypertension are not only risk factors for development of EOFGR, but also markers of its severity. Doppler abnormalities on the last ultrasound prior to delivery are more predictive of adverse outcome than amniotic fluid abnormalities, and development of co-existent pre-eclampsia confers higher risk. This information provides valuable insights for clinicians caring for these high-risk pregnancies.