Antenatal detection of fetal growth restriction and stillbirth risk: a population‐based case–control study

BACKGROUND: Antenatal surveillance of intrauterine growth aims to detect growth restricted fetuses who face higher risks of stillbirth. Improving detection could be an effective strategy for stillbirth prevention. The REPERE study was conducted to estimate the association between antenatal detection of small for gestational age (SGA) and stillbirth risk in France. METHODS: REPERE is a case-control study performed in 3 French districts with approximately 30,000 births annually. Cases were singleton SGA stillbirths at ≥24 weeks of gestational age (GA) without severe congenital anomalies from 2012 to 2014 identified using a population-based stillbirth registry; controls were live births fulfilling the same inclusion criteria over 3 months in 2014. Data were abstracted from medical records and ultrasound reports by trained investigators. SGA was defined as a birthweight under the 10th percentile of French customized standards. Detection of fetal growth restriction (FGR) was defined by the presence of at least one of seven predefined parameters (FGR or growth faltering mentioned in medical records or ultrasound reports, documented abdominal circumference or estimated fetal weight <10th percentile, prescription of additional ultrasounds to monitor growth or abnormal umbilical Doppler). We used logistic regression to estimate crude and adjusted odds ratios (OR) of the association of detection with stillbirth risk. Co-variables were clinical factors, including parity, maternal medical history, vascular complications during pregnancy and birthweight percentile, which are associated with risks of detection and of stillbirth. RESULTS: Out of 92,182 births at ≥22 weeks GA, there were 669 stillbirths of which 79 fulfilled inclusion criteria. 44.3% of cases (35/79) were detected versus 36.2% of controls (154/426). The crude OR measuring the impact of detection on stillbirth risk was 1.4 (95% CI 0.9 to 2.3) and declined to 0.6 (95% CI 0.3 to 1.0) after adjustment. Among births at ≥28 weeks GA, detection rates were 38.3 versus 36.0% among cases and controls with an adjusted OR of 0.5 (95% CI: 0.2 to 1.0)). CONCLUSION: Antenatal detection of FGR was protective against stillbirth, but over 40% of stillbirths among SGA fetuses occurred despite detection, pointing to the need to improve management after detection. This article is protected by copyright. All rights reserved.