Prospective evaluation of the first-trimester screening strategy for preterm pre-eclampsia and its clinical applicability in China.

OBJECTIVES To evaluate the performance of screening strategy for preterm preeclampsia using the Fetal Medicine Foundation (FMF)'s competing risk model in mainland China and to explore its clinical applicability. METHODS A prospective multicenter study was conducted and 10,899 singleton pregnancies were included, Mean arterial pressure (MAP), uterine artery pulsatility index (UtPI), maternal serum levels of placental growth factor (PlGF) and pregnancy associated plasma protein A (PAPPA) at 11-13 weeks' gestation were measured and converted into multiples of median according to localized parameters, individualized risk stratification was calculated using FMF's algorithm. Prior risk was calculated based on maternal characteristics and obstetric history information. The efficiency of screening strategy with various biomarker combined was evaluated, and the detection performance for other placenta-associated adverse pregnancy outcomes at fixed false positive rate for preterm preeclampsia was also analyzed. RESULTS A total of 312 pregnancies developed preeclampsia, among which 117 cases were diagnosed as preterm, 386 pregnancies were complicated by severe composite placenta-associated pregnancy outcomes, including preterm preeclampsia, 146 cases severe small for gestational age (SGA<3rd percentile), 61 cases placenta abruption, and 109 cases preterm birth delivered before 34 gestational weeks. The model containing biomarker MAP, UtPI and PAPPA achieved detection rates of 65.0 %, 72.6%, and 76.1% for preterm preeclampsia, and detection rates of 35.8%, 40.4%, 45.0% for severe composite placenta-associated outcomes, at 10%, 15%, and 20% fixed false-positive rates for preterm pre-eclampsia, respectively. Replacing PAPPA with PlGF or adding PlGF cannot improve the performance. For women screened positive for preterm preeclampsia at fixed 5% false positive rate, an estimated of 30% ended up with at least one placenta-associated pregnancy outcomes, including preeclampsia, placenta abruption, SGA(<10th percentile) and preterm birth. CONCLUSION The results of this population study showed that the FMF's competing-risk model for preterm preeclampsia was effective in mainland China. Women who screened as positive for preterm pre-eclampsia had an increased risk for other placenta-associated pregnancy complications. This article is protected by copyright. All rights reserved.