Preeclampsia prevention by timed birth at term: a randomised trial
Pre-eclampsia
Current interventions as of 27/02/2026: Randomisation will be provided by a computer-generated programme hosted by King's Clinical Trials Unit, in random permuted blocks, using a minimisation algorithm to ensure balance in the treatment allocation stratified for participating sites. Intervention group: Screening for PE at 35-36 weeks’ gestation (by a combination of maternal factors, MAP, PlGF and sFlt-1) and planned early-term delivery if the risk for PE is increased, at a risk of at least 1 in 50. Screening for PE will be undertaken by the ‘competing-risks model’ FMF algorithm that combines maternal demographics and medical history, MAP and maternal serum sFlt-1 and PlGF to provide a personalised risk of PE. MAP will be measured by validated automated devices and a standardised protocol. Serum sFlt-1 and PlGF concentrations will be measured by an automated device (BRAHMS KRYPTOR compact PLUS, Thermo Fisher Scientific, Hennigsdorf, Germany). Women will have a planned initiation of early-term delivery, according to their risk of PE, as follows: Intervention group: PE risk ≥1 in 2 will have planned delivery at 37+0 - 37+2 weeks PE risk 1 in 3 to 1 in 5 will have planned delivery at 38+0 - 38+2 weeks PE risk 1 in 6 to 1 in 20 will have planned delivery at 39+0 – 39+2 weeks PE risk 1 in 21 to 1 in 50 will have planned delivery at 40+0 – 40+2 weeks PE risk <1 in 50 will have planned delivery at 41+ weeks (per local policy) Control group: Usual care Birth will await the onset of spontaneous labour or development of a clinical need for delivery, as per relevant NICE or RCOG clinical guidance on the timing of birth in general (ng207) or specific to maternal or fetal conditions (e.g., NG133 for pregnancy hypertension) Previous interventions: Randomisation will be provided by a computer-generated programme hosted by King's Clinical Trials Unit, in random permuted blocks, using a minimisation algorithm to ensure balance in the treatment allocation stratified for particip
1. Singleton pregnancy 2. Live fetus at 35+0-36+6 weeks’ gestation 3. Able to provide informed and documented consent
1. Age <16 years 2. Women with established PE 3. Known major fetal abnormality 4. Participating in another intervention study that influences the outcomes of this study