Prediction of preeclampsia by mean arterial pressure at 11-13 and 20-24 weeks' gestation.

OBJECTIVES To assess the performance of screening for preeclampsia (PE) by mean arterial pressure (MAP) at 11-13 and at 20-24 weeks' gestation. METHODS MAP was measured at 11-13 and 20-24 weeks in 17,383 singleton pregnancies, including 70 with early PE, requiring delivery <34 weeks' gestation, 143 with preterm PE, delivering <37 weeks and 537 with total PE. MAP was expressed as multiple of the median (MoM) after adjustment for maternal characteristics and corrected for adverse pregnancy outcomes. The performance of screening for PE by maternal characteristics and MAP MoM at 11-13 weeks (MAP-1), MAP MoM at 20-24 weeks (MAP-2) and their combination was evaluated. RESULTS In screening by maternal characteristics and MAP-1, at a false-positive rate (FPR) of 10%, the detection rates (DR) of early PE, preterm PE and total PE were 74.3, 62.9 and 49.3%, respectively; the DR at FPR of 5% were 52.9, 42.7 and 35.8%. In screening by MAP-1 and MAP-2 the DR at FPR of 10%, were 84.3, 65.7 and 52.5%; the DR at FPR of 5% were 60.0, 49.7 and 37.6%, respectively. CONCLUSIONS Performance of screening for PE by MAP is best when measurements are taken at both 11-13 and 20-24 weeks' gestation than at only one of these gestational ranges.