Prognosis for fetuses with isolated severe growth retardation from 23 gestational weeks with an initial assessment unfavorable to an active management

Objective: To study perinatal outcomes for newborns with early, isolated, severe FGR, for whom initial active management was considered unreasonable or impossible at an obstetric-pediatric assessment and to identify the determinants associated with a course that made active management reasonable.

Material and methods: This retrospective observational single-center study occurred in a level-3 university hospital maternity unit. It included all pregnancies with a singleton fetus presenting isolated FGR <3rd percentile at 23 weeks or more of gestation with an obstetric-pediatric assessment (OPA) initially unfavorable to active management. The main outcome measure was perinatal mortality. Characteristics of the women and pregnancies were compared between the groups "OPA became favorable" versus "OPA remained unfavorable".

Results: Among the 80 cases included, 48 (60%) of the children died, 38 (47.5%) before birth, 2 (2.5%) in the delivery room, and 8 (10%) in the NICU. Overall, the OPA for 32 (40%) became favorable. There were 44 (91.7%) perinatal deaths when the OPA remained unfavorable versus 4 (12.5%) when it became favorable (P<0.001). The median gestational age at the first OPA (25 weeks) did not differ between the groups. The patients in the OPA became favorable group had initially abnormal uterine Doppler findings less often (56.2% vs 85.4%, P=0.001), absent diastole or reverse flow umbilical artery less often (9.4% vs 33.3%, P=0.0016), less preeclampsia (6.2% vs 31.2%, P=0.009) and a higher estimated fetal weight (520 [491-546] g vs 487 [449-523] g, P=0.005).

Conclusion: In fetuses with early severe FGR, the risk of perinatal death was very high when the initial OPA was unfavorable. Initial OPA without preeclampsia and umbilical reverse diastolic flow were associated with higher probability that the OPA became favorable.