Diagnostic accuracy of placental growth factor and ultrasound parameters to predict the small‐for‐gestational‐age infant in women presenting with reduced symphysis–fundus height

OBJECTIVES: To assess the diagnostic accuracy of placental growth factor (PlGF) and ultrasound parameters to predict delivery of a small‐for‐gestational‐age (SGA) infant in women presenting with reduced symphysis–fundus height (SFH). METHODS: This was a multicenter prospective observational study recruiting 601 women with a singleton pregnancy and reduced SFH between 24 and 37 weeks' gestation across 11 sites in the UK and Canada. Plasma PlGF concentration < 5(th) centile, estimated fetal weight (EFW) < 10(th) centile, umbilical artery Doppler pulsatility index > 95(th) centile and oligohydramnios (amniotic fluid index < 5 cm) were compared as predictors for a SGA infant < 3(rd) customized birth‐weight centile and adverse perinatal outcome. Test performance statistics were calculated for all parameters in isolation and in combination. RESULTS: Of the 601 women recruited, 592 were analyzed. For predicting delivery of SGA < 3(rd) centile (n = 78), EFW < 10(th) centile had 58% sensitivity (95% CI, 46–69%) and 93% negative predictive value (NPV) (95% CI, 90–95%), PlGF had 37% sensitivity (95% CI, 27–49%) and 90% NPV (95% CI, 87–93%); in combination, PlGF and EFW < 10(th) centile had 69% sensitivity (95% CI, 55–81%) and 93% NPV (95% CI, 89–96%). The equivalent receiver–operating characteristics (ROC) curve areas were 0.79 (95% CI, 0.74–0.84) for EFW < 10(th) centile, 0.70 (95% CI, 0.63–0.77) for low PlGF and 0.82 (95% CI, 0.77–0.86) in combination. CONCLUSIONS: For women presenting with reduced SFH, ultrasound parameters had modest test performance for predicting delivery of SGA < 3(rd) centile. PlGF performed no better than EFW < 10(th) centile in determining delivery of a SGA infant. © 2015 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the international society of ultrasound in obstetrics and gynecology.