Severe smallness as predictor of adverse neonatal outcome in suspected late SGA fetuses: systematic review and meta‐analysis

To investigate the performance of severe smallness (estimated fetal weight [EFW] <3rd percentile) among suspected small-for-gestational-age (SGA) fetuses for the prediction of adverse perinatal outcomes.A systematic search was launched to identify relevant studies held by the most relevant electronic databases. Random-effects modelling served to generate hierarchical summary receiver-operating characteristic curves (HSROCs). The performance of severe SGA among singleton pregnancies (as presumptive diagnosis) in predicting adverse perinatal outcome was expressed as area under the curve (AUC), sensitivity (Se), specificity (Sp), and positive (+LR)/negative (-LR) likelihood ratios. The association between suspected severe SGA and adverse perinatal outcome was additionally assessed by random-effects modelling, using Mantel-Haenszel method, and presented as odds ratio (OR). The non-exposed group was defined as non-severe SGA (EFW≥ 3rd centile).The 12 cohort studies selected included 3,639 fetuses with suspected SGA (in which 1,246 severe SGA was suspected). Significant associations were found between suspected severe SGA and composite adverse perinatal outcome (OR=1.97, confidence interval [CI]: 1.33-2.92), neonatal unit admission (OR=2.87, CI: 1.84-4.47), and perinatal death (OR=4.26, CI: 1.07-16.93). However, summary ROC curves showed limited performance of suspected severe SGA for all outcomes, with AUCs of 60.9, 66.9, 53.6, 57.2, 54.6, and 64.9 for composite adverse perinatal outcome, neonatal unit admission, neonatal acidosis, emergency caesarean section, low Apgar score, and perinatal death, respectively.Although associated with a higher risk for perinatal complications, suspected severe SGA performed poorly as a standalone parameter in predicting adverse perinatal outcomes. This article is protected by copyright. All rights reserved.