Prediction of stillbirth from maternal factors, fetal biometry and uterine artery Doppler at 19-24 weeks

Objectives: To evaluate the performance of screening for all stillbirths and those due to impaired placentation and unexplained or other causes by a combination of maternal factors, fetal biometry and uterine artery pulsatility index (UT-PI) at 19-24 weeks’ gestation and compare this performance to that of screening by UT-PI alone.<br /><br />Methods: This was a prospective screening study of 70,003 singleton pregnancies including 69,735 live births and 268 (0.38%) antepartum stillbirths; 159 (59%) were secondary to impaired placentation and 109 (41%) were due to other or unexplained causes. Multivariate logistic regression analysis was used to develop a model for prediction of stillbirth based on a combination of maternal factors, fetal biometry and UT-PI.<br />Results: Combined screening predicted 55% of all stillbirths, including 75% of those due to impaired placentation and 23% of those that were due to other causes or unexplained, at false positive rate of 10%; within the impaired placentation group the detection rate of stillbirth at <32 weeks’ gestation was higher than that of stillbirth at >37 weeks (88% vs 46%; p<0.001). The performance of screening by the combined test was superior to that of selecting the high-risk group on the basis of UT-PI being above the 90th percentile for gestational age, which predicted 48% of all stillbirths, 70% of those due to impaired placentation and 15% of those that were due to other causes or unexplained.<br /><br />Conclusions: Second-trimester screening by a combination of UT-PI with maternal factors and fetal biometry can predict a high proportion of stillbirths and in particular those due to impaired placentation.