Accuracy of competing-risks model in screening for pre-eclampsia by maternal factors and biomarkers at 11-13 weeks' gestation

Objective: To examine the diagnostic accuracy of a previously developed model for prediction of preeclampsia (PE) by a combination of maternal factors and biomarkers at 11-13 weeks’ gestation.<br /><br />Methods: This was a prospective first-trimester multicenter study of screening for PE in 8,775 singleton pregnancies. A previously published algorithm was used for the calculation<br />of patient-specific risk of PE in each patient. The detection rates (DR) and false positive rates (FPR) for delivery with PE at <32, <37 and >37 weeks were estimated and compared<br />to those in the dataset used for development of the algorithm.<br /><br />Results: In the study population there were 239 (2.7%) cases that developed PE, including 17 (0.2%), 59 (0.7%) and 180 (2.0%) at <32, <37 and >37 weeks, respectively. In combined screening by maternal factors, mean arterial pressure, uterine artery pulsatility index and serum placental growth factor the DR was 100% (95% CI 80-100) for PE at <32 weeks, 75% (95% CI 62-85) for PE at <37 weeks and 43% (95% CI 35-50) for PE at >37 weeks, at 10% FPR. These DRs were similar to the estimated rates in the dataset used for development of<br />the model: 89% (95% CI 79-96) for PE at <32 weeks, 75% (95% CI 70-80) for PE at <37 weeks and 47% (95% CI 44-51) for PE at >37 weeks.<br /><br />Conclusion: Combination of maternal factors and biomarkers provides effective firsttrimester screening for preterm-PE.