Predicting delivery of a small-for-gestational-age infant and adverse perinatal outcome in women with suspected pre-eclampsia

Objective: To evaluate the test performance of 47 biomarkers and ultrasound parameters for the prediction of delivery of a small-for-gestational-age (SGA) infant and adverse perinatal outcome in women presenting with suspected pre-eclampsia. Methods: This was a prospective, multicenter observational study in which 47 biomarkers and ultrasound parameters were measured in 397 women with a singleton pregnancy presenting with suspected preterm pre-eclampsia between 20+0 and 36+6 weeks' gestation, with the objective of evaluating them as predictors of subsequent delivery of a SGA infant and adverse perinatal outcome. Women with confirmed pre-eclampsia at enrollment were excluded. Factor analysis and stepwise logistic regression were performed in two prespecified groups stratified according to gestational age at enrollment. The primary outcome was delivery of a SGA infant with a birth weight <3^rd customized centile (SGA-3), and secondary outcomes were a SGA infant with a birth weight <10^th customized centile and adverse perinatal outcome. Results: In 274 women presenting at 20+0 to 34+6 weeks' gestation, 96 (35%) delivered a SGA-3 infant. For prediction of SGA-3, low maternal placental growth factor (PlGF) concentration had a sensitivity of 93% (95% CI, 84-98%) and negative predictive value (NPV) of 90% (95% CI, 76-97%) compared with a sensitivity of 71% (95% CI, 58-82%) and a NPV of 79% (95% CI, 68-87%) for ultrasound parameters (estimated fetal weight or abdominal circumference <10^th centile). No individual biomarker evaluated had a better performance than did PlGF, and marker combinations made only small improvements to the test performance. Similar results were found in 123 women presenting between 35+0 and 36+6 weeks' gestation. Conclusion: In women presenting with suspected preterm pre-eclampsia, measurement of PlGF offers a useful adjunct for identifying those at high risk of delivering a SGA infant, allowing appropriate surveillance and timely intervention.