Preeclampsia is a pregnancy complication marked by new-onset high blood pressure and signs of stress on organs such as the kidneys, liver, and brain. While much attention is often given to preterm disease, about 75% of preeclampsia cases occur at term (37 weeks or later). These term cases account for more than half of serious maternal complications and about one quarter of major fetal or newborn illness or death.

The Fetal Medicine Foundation (FMF), an international organization based in the United Kingdom, developed a calculator to estimate an individual’s risk of developing preeclampsia. When used early in pregnancy, this tool is effective at identifying people who will develop preterm preeclampsia but is less accurate for predicting disease at term. Term preeclampsia develops later and often more subtly, making it harder to detect in advance. Prediction improves when screening is done closer to delivery, at 35–36 weeks.

Low-dose aspirin can reduce the risk of preterm preeclampsia by about 60%, but it does not reduce the risk of term disease. At present, there is no proven medical treatment to prevent term preeclampsia except possibly earlier delivery. Prior studies have shown that early-term delivery in women with chronic hypertension (CHTN)—high blood pressure that existed before pregnancy or before 20 weeks—and elective delivery at 39 weeks in nulliparous women (those who have not previously given birth) lowers the incidence of preeclampsia. This study, known as PREVENT-PE, was designed to determine whether screening women at 35–36 weeks and offering planned early delivery to those at higher risk could safely reduce term preeclampsia.

Participants were recruited from two large maternity units in the UK where ultrasounds are routinely performed at 35–36 weeks to assess fetal growth and help plan delivery. Women were randomly assigned to an intervention group or a control group, which received usual pregnancy and delivery care. In the intervention group, preeclampsia risk was calculated using the FMF tool, which included maternal characteristics, medical and pregnancy history, current blood pressure, and blood levels of placental markers—placental growth factor (PlGF), which is typically low, and sFlt-1, which is typically high in those who develop preeclampsia. Women with a calculated risk greater than 1 in 50 were advised to deliver between 37 and 40 weeks, depending on their level of risk. Those with lower risk continued routine care.

A total of 8,094 women participated. Of the 885 women who screened positive and were offered early delivery, nearly 83% delivered at the recommended time. Preeclampsia occurred in 3.9% of the intervention group compared with 5.6% of the control group, representing a significant reduction. Rates of cesarean delivery were similar between groups, and there were no differences in newborn intensive care unit (NICU) admissions lasting 48 hours or more or in postpartum preeclampsia. Maternal complications such as protein in the urine, low platelet counts, and organ dysfunction were less common in the intervention group. Serious adverse events were rare in both groups.

These findings suggest that term preeclampsia, which is harder to predict because it develops later in pregnancy, may be prevented in some patients by identifying risk close to delivery and planning birth before the condition fully develops.

Take Home Message: Planned early-term birth based on risk stratification for preeclampsia reduced the incidence of preeclampsia without increasing emergency cesarean delivery or NICU admission. Because this study was conducted in the UK, additional studies are needed to determine how this approach would translate to the United States. Most importantly, the results highlight the value of shared decision-making between patients and providers when determining the timing of delivery to achieve the best outcomes for both mother and baby.

Citation: James Goadsby, Argyro Syngelaki, Laura Magee, Peter von Dadelszen, Ranjit Akolekar, Sophie Webster, Alan Wright, David Wright & Kypros H Nicolaides.  Lancet 2026;407:67-77.

Link: https://www.thelancet.com/retrieve/pii/S0140673625012073

About Research Roundup:

Each quarter, our team of science writers reviews the most current research studies related to hypertensive disorders of pregnancy and summarizes those studies of greatest interest and potential impact to our community, including research studies related to risk assessment, diagnosis, prevention, and treatment. Special thanks to our volunteer research team including Dr. Sig-Linda Jacobson, Dr. Jennifer Mitchell, Dr. Julie Reynolds, Amanda Yang, and Simren Gupta who make Research Roundup possible, and to our Patient Advisory Council, who reviews these materials from the patient perspective.