A 36-week screening strategy safely reduces pre-eclampsia at term

By Dr. Liji Thomas, MDReviewed by Lauren HardakerDec 8 2025

By pairing late-pregnancy risk screening with personalised timing of birth, researchers show how term pre-eclampsia can be safely prevented, offering a new strategy that could reshape late-pregnancy care for women at highest risk.

Study: Scheduled birth at term for the prevention of pre-eclampsia (PREVENT-PE): an open-label randomised controlled trial. Image Credit: SeventyFour / Shutterstock

Pre-eclampsia is among the most common hypertensive disorders of pregnancy and can have fatal outcomes for both mother and baby. There is currently no proven intervention to reliably reduce the incidence of term pre-eclampsia. A recent study in The Lancet sought to examine whether screening for the condition at 36 weeks of pregnancy, followed by risk-stratified planned early-term (37 to 40 weeks) delivery, could effectively reduce pre-eclampsia rates in singleton pregnancies managed within a UK maternity care setting.

Burden and Predictive Challenges of Term Pre-eclampsia

Pre-eclampsia is a major cause of severe illness and death among pregnant women and their babies, complicating on average 3% of pregnancies. Approximately 75% occur at term, 37 completed weeks of gestation or later, and account for over half of maternal deaths and a quarter or more of perinatal deaths or severe illness.

The Fetal Medicine Foundation (FMF) competing-risks model, applied at 11–13 weeks, identifies about 10% of screened women as positive. It is able to correctly predict 75% of women who will develop preterm pre-eclampsia, compared to the 40% rate picked up by using only clinical factors.

The use of preventive aspirin in high-risk women can reduce preterm pre-eclampsia rates by about 60%. However, this does not significantly reduce the incidence of term pre-eclampsia.

The FMF competing-risks model can be used at 35–36 weeks to predict late preterm and term pre-eclampsia, detecting about 70% of these subjects. Unfortunately, effective preventive therapies are lacking in this group.

The current study sought to build on earlier research suggesting that elective induction of delivery at term could reduce the rates of term pre-eclampsia. Both a Cochrane systematic review and a randomized trial of low-risk nulliparous women randomly assigned to early-term birth suggest the benefits of this approach, supported by large-scale prospective observational data on the use of pre-eclampsia screening at 36 weeks and planned early-term birth in at-risk women.

Design and Eligibility of the PREVENT-PE Trial

The data came from PREVENT-PE, an open-label randomized controlled trial carried out at two maternity hospitals in the UK. Participants were women aged 16 years or older, with a single fetus without major congenital anomalies. None had pre-eclampsia at baseline.

All eligible women were randomly assigned to the intervention or control group before risk stratification. Pre-eclampsia risk was then evaluated at 36 weeks using the FMF competing-risks model, which includes:

• Maternal factors like age, body weight, ethnicity, and method of conception • A medical history predisposing to hypertensive disorders in pregnancy, including chronic hypertension or diabetes, a prior history or family history of pre-eclampsia, and systemic lupus erythematosus • Serum biomarkers (placental growth factor and soluble fms-like tyrosine kinase-1) • The mean arterial pressure

Women in the intervention group who were identified as high-risk, defined as having a pre-eclampsia risk of 1 in 50 or higher, were offered risk-stratified planned birth between 37 and 40 weeks, with higher-risk women scheduled earlier. The majority of women in the intervention group (around 78%) were classified as low risk and therefore received usual pregnancy care. Women in the control group received usual pregnancy care, regardless of risk status.

Participant Characteristics and Screening Outcomes

Of the 8,094 women included in the final analyses, the mean age was in the early thirties, and most had body mass indices in the high-overweight range. Most (74%) were White. About half were expecting their first child, with 3% having had one or more prior pregnancies complicated by pre-eclampsia. Approximately 4% had a family history of pre-eclampsia.

The FMF competing-risks model was applied at 36 weeks because its predictions for term pre-eclampsia are most accurate at this point. A timed birth plan was developed in the intervention group based on each woman’s estimated risk. About 7% of fetuses were classified as small-for-gestational-age, and a similar proportion were large-for-gestational-age. Approximately 17% of women were taking preventive aspirin.

Risk-Stratified Planned Birth Reduces Term Pre-eclampsia

Among the 4,037 births in the intervention group, pre-eclampsia occurred in 158 women, or about 4%, compared with 226 cases (5.6%) among 4,057 women in the control group. This corresponded to a 30% relative reduction in the risk of pre-eclampsia in the intervention group, when analysed according to the intention-to-treat principle, using the International Society for the Study of Hypertension in Pregnancy (ISSHP) 2021 diagnostic criteria.

There was no difference in serious adverse events between groups, with rates below 0.3% in both. Importantly, there was no increase in postpartum pre-eclampsia, no rise in emergency Caesarean section delivery, and no increase in neonatal intensive care unit admissions among babies born to women in the intervention group.

Notably, approximately 75% of eligible women chose to participate in the trial, with very few withdrawing or being lost to follow-up. This high participation rate suggests that risk-based timed birth at term is acceptable to many women. Further evaluation of the direct and indirect costs of this strategy is planned, alongside qualitative analyses capturing the experiences of participating women and clinical staff.

Implications for Term Pre-eclampsia Prevention Strategies

Planned birth at early term in women identified as being at high risk for pre-eclampsia may reduce the incidence of pre-eclampsia when guided by personalised risk assessment at 36 weeks, without increasing serious maternal or neonatal complications. This is the first randomised trial to report such findings using a personalised, risk-stratified approach to the prevention of term pre-eclampsia within a routine maternity care pathway that includes a 36-week birth-plan ultrasound.

Following appropriate acceptability and cost-effectiveness analyses, the researchers suggest that these findings could inform future clinical guidelines for managing pregnant women at high risk of term pre-eclampsia.