Lamain-de Ruiter, MarijeKwee, AnnekeNaaktgeboren, Christiana ALouhanepessy, Rebecca DDe Groot, IngeEvers, Inge MGroenendaal, FlorisHering, Yolanda RHuisjes, Anjoke J MKirpestein, CornelMonincx, Wilma MSchielen, Peter C J IVan 't Zelfde, AnnewilVan Oirschot, Charlotte MVankan-Buitelaar, Simone AVonk, Mariska A A WWiegers, Therese AZwart, Joost JMoons, Karel G MFranx, ArieKoster, Maria P H2019-03-282019-03-282019-03-201525-60653089298110.1080/10641955.2019.1584210http://hdl.handle.net/10029/622990To perform an external validation of all published prognostic models for first-trimester prediction of the risk of developing preeclampsia (PE). Women <14 weeks of pregnancy were recruited in the Netherlands. All systematically identified prognostic models for PE that contained predictors commonly available were eligible for external validation. 3,736 women were included; 87 (2.3%) developed PE. Calibration was poor due to overestimation. Discrimination of 9 models for LO-PE ranged from 0.58 to 0.71 and of 9 models for all PE from 0.55 to 0.75. Only a few easily applicable prognostic models for all PE showed discrimination above 0.70, which is considered an acceptable performance.enFirst trimesterexternal validationpreeclampsiaprognostic modelArticleHypertens Pregnancy 2019; advance online publication (ahead of print)