Prediction of stillbirth from biochemical and biophysical markers at 11-13 weeks

Objectives: To develop a model for prediction of stillbirth based on a combination of maternal characteristics and medical history with first trimester biochemical and biophysical markers and evaluate the performance of screening of this model for all stillbirths and those due to impaired placentation and unexplained causes.<br /><br />Methods: This was a prospective screening study of 76,897 singleton pregnancies including 76,629 live births and 268 (0.35%) antepartum stillbirths; 157 (59%) were secondary to impaired placentation and 111 (41%) were due to other or unexplained causes. Multivariate logistic regression analysis was used to determine if there was a significant contribution to prediction of stillbirth from the maternal factor-derived a priori risk, fetal nuchal translucency thickness (NT), ductus venosus pulsatility index for veins (DV-PIV), uterine artery pulsatility index (UT-PI) and maternal serum free ß-human chorionic gonadotrophin ((ß-hCG) and pregnancy associated plasma protein-A (PAPP-A). The significant contributors were used to derive a model for first-trimester prediction of stillbirth.<br /><br />Results: Significant contribution to prediction of stillbirth was provided by maternal factors, PAPP-A, UT-PI and DV-PIV. A model combining these variables predicted 40% of all stillbirths and 55% of those due to impaired placentation, 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 (64% vs 42%).<br />Conclusions: A model based on maternal factors and first-trimester biomarkers can potentially predict more than half of subsequent stillbirths due to impaired placentation. The extent to which such stillbirths could be prevented remains to be determined.