<scp>sFlt</scp>‐1/<scp>PlGF</scp> ratio and timing of delivery in early‐onset fetal growth restriction with antegrade umbilical artery flow

Abstract

ABSTRACT Objective To analyze the value of the soluble fms‐like tyrosine kinase‐1/placental growth factor (sFlt‐1/PlGF) ratio in predicting the time to delivery in early‐onset fetal growth restriction (FGR) with preserved antegrade umbilical artery (UA) flow at diagnosis. Methods This was a prospective observational single‐center cohort study of pregnancies with early‐onset (&lt; 32 + 0 weeks) FGR and antegrade UA flow, in which maternal serum sFlt‐1/PlGF ratio was determined at diagnosis. FGR was defined as estimated fetal weight &lt; 3 rd centile or &lt; 10 th centile with UA pulsatility index &gt; 95 th centile, fetal middle cerebral artery pulsatility index &lt; 5 th centile or cerebroplacental ratio &lt; 5 th centile. The previously described sFlt‐1/PlGF ratio cut‐off value of 85 for facilitating the diagnosis of pre‐eclampsia was assessed in the prediction of the need to deliver in &lt; 1 week and ≥ 4 weeks. Results In total, 120 cases were included. There were 116 (96.7%) liveborn neonates and 108 (90.0%) perinatal survivors. Median (interquartile range (IQR)) gestational age at diagnosis of early‐onset FGR was 27.1 (25.7–29.4) weeks. Median (IQR) sFlt‐1/PlGF ratio at diagnosis was 196 (84–474). Ninety (75.0%) cases had a sFlt‐1/PlGF ratio ≥ 85. Among pregnancies with a liveborn neonate, median (IQR) interval to delivery in the groups with sFlt‐1/PlGF ratio &lt; 85 and ≥ 85 was 41 (22–54) days and 11 (4–20) days, respectively ( P &lt; 0.01). The probability of having to deliver within 1 week after diagnosis was 0% and 35.6% in those with sFlt‐1/PlGF ratio &lt; 85 and ≥ 85, respectively ( P = 0.03), and the probability of delaying delivery for ≥ 4 weeks was 72.4% and 19.5%, respectively ( P &lt; 0.01). Conclusion sFlt‐1/PlGF ratio &lt; 85 at diagnosis of early‐onset FGR with antegrade UA flow identifies a group of pregnancies in which the need to deliver within 1 week is very low and the interval to delivery is expected to be prolonged for ≥ 4 weeks in &gt; 70% of cases. Copyright © 2019 ISUOG. Published by John Wiley &amp; Sons Ltd.