Prediction of small-for-gestational-age neonates: screening by maternal biochemical markers at 30-34 weeks

Objective To investigate the potential value of serum placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), pregnancy-associated plasma protein-A (PAPP-A), free beta-human chorionic gonadotropin (beta-hCG) and a-fetoprotein (AFP) at 30-34 weeks' gestation in the prediction of delivery of small-for-gestational-age (SGA) neonates, in the absence of pre-eclampsia (PE). Methods This was a screening study in singleton pregnancies at 30-34 weeks' gestation, including 490 that delivered SGA neonates and 9360 cases that were unaffected by SGA, PE or gestational hypertension (normal outcome). Multivariable logistic regression analysis was used to determine if screening by serum PlGF, sFlt-1, PAPP-A, free beta-hCG and AFP, individually or in combination, improved the prediction of SGA neonates provided by screening with maternal characteristics and medical history (maternal factors), and estimated fetal weight (EFW) from fetal head circumference, abdominal circumference and femur length. Results Compared to the normal group, the mean log(10) multiples of the median (MoM) values of PlGF and AFP were significantly lower and the mean log(10) MoM values of sFlt-1 and free beta-hCG were significantly higher in the SGA group with a birth weight < 5th percentile (SGA < 5th) delivering < 5weeks following assessment. The best model for prediction of SGA was provided by a combination of maternal factors, EFW and serum PlGF. Such combined screening, predicted, at a 10% false-positive rate, 85%, 93% and 92% of SGA neonates delivering < 5weeks following assessment with birth weight < 10th, < 5th and < 3rd percentiles, respectively; the respective detection rates of combined screening for SGA neonates delivering >= 5weeks following assessment were 57%, 64% and 71%. Conclusion Combined screening by maternal factors, EFW and serum PlGF at 30-34 weeks' gestation can identify a high proportion of pregnancies that subsequently deliver SGA neonates. Copyright (C) 2015 ISUOG. Published by John Wiley & Sons Ltd.