305 A predictive index for severe adverse perinatal outcomes in pregnancies complicated by fetal growth restriction

Abstract

Lack of significance of several covariates in a model we recently validated indicated model reconstruction may improve its performance. Our aim was to redevelop the model and then use it to develop an index predictive of severe adverse perinatal outcomes in pregnancies complicated by fetal growth restriction (FGR). Data was derived from a cohort of singleton non-anomalous gestations meeting Delphi procedure-based consensus criteria [Gordijn S et al. Ultrasound Obstet Gynecol 2016;48(3):333-9] for FGR between 2010-2020 at a single tertiary-care institution. The cohort was retrospectively analyzed according to the occurrence of composite adverse perinatal outcome: perinatal demise, 5-minute Apgar < 7, cord pH ≤ 7.1, or cord base excess ≥ 12. Regression analysis incorporated clinical factors widely available at the time of growth restriction diagnosis. The sum of beta coefficient-based weights yielded a severe adverse perinatal outcome index score. Of the 907 pregnancies that met criteria for FGR, 226 (25%) were complicated by severe adverse perinatal outcomes. 278 (31%) were delivered by cesarean for non-reassuring fetal status and 410 (45%) neonates were admitted to the NICU. The derived index included nine clinical factors: maternal age ≥ 30, body mass index ≥ 40, nulliparity, male fetus, gestational age ≤ 28 weeks, hypertensive disorder of pregnancy both with and without chronic hypertension, umbilical artery absent or reversed end diastolic flow, and gestational diabetes. The index’s bootstrapped bias-corrected AUC was 0.78 (95% CI 0.74-0.81). Index sum cut-points were selected to identify “high risk” (≥ 10) and “low risk” (≤ 4) ranges that have positive and negative predictive values of 73% (95% CI 63-81%) and 88% (95% CI 86-90%), respectively. An index incorporating nine clinical factors widely available at time of growth restriction diagnosis was predictive of severe adverse perinatal outcomes. If validated, the index may prove useful in counseling and management of pregnancies meeting consensus-based criteria for fetal growth restriction.View Large Image Figure ViewerDownload Hi-res image Download (PPT)