All women with singleton pregnancies who are attending for their routine hospital visit at 11-13 weeks' gestation will be invited to undergo screening for preeclampsia. We use a Bayes theorem-based method that combines maternal characteristics, medical and obstetric history together with mean arterial pressure (MAP) and serum placental growth factor (PlGF) level. Women who are deemed high-risk following first trimester combined screening (cutoff corresponding to a screen positive rate of 10%, e.g ≥1 in 80) will be invited to participate in the 3-arm randomized controlled trial.