Young, White pregnant woman with light brown hair sitting on bed and holding head to represent having preeclampsia, a condition of pregnancy involving high blood pressure
Credit: DjelicS/ Getty Images

Screening for preeclampsia using a combination of maternal history, ultrasound screening, and a panel of blood biomarkers could help improve early detection rates of the condition, which could improve both maternal and infant health in those affected.

Writing in the journal Hypertension, lead study author Emmanuel Bujold, MD, professor in the department of obstetrics and gynecology at the Université Laval in Canada, and colleagues report that their screening test was more accurate at detecting both preterm and early onset preeclampsia than currently recommended methods, which focus on maternal demographic or medical historical risk factors alone.

Preeclampsia affects approximately 1 in 25 pregnancies in the United States. The main symptom of the condition is having an abnormally high blood pressure during pregnancy and can be life-threatening for both the mother and baby if left untreated. It impacts fetal growth and other developmental factors and can lead to long-term cardiovascular problems for women who are affected while pregnant.

Although the changes in the mother’s body that lead to preeclampsia start in the very early stages of pregnancy (weeks 1–12), more obvious symptoms are not normally seen before 20 weeks of pregnancy meaning the condition it often diagnosed at a late stage. Late-stage diagnosis invariably leads to early delivery of the baby. Earlier diagnosis would beneficial as it means there is a possibility to ward off the condition through prophylactic treatments such as low dose aspirin, which was estimated in an earlier study to reduce preeclampsia risk by 53% if started early in pregnancy (pre 16 weeks).

The current study assessed the accuracy of an algorithm developed by the Fetal Medicine Foundation in the U.K. at predicting preeclampsia. The algorithm combines maternal history, ultrasound results, body mass index, blood pressure, and measurement of biochemical blood biomarkers such as pregnancy-associated plasma protein A and placental growth factor to predict risk at an early stage of pregnancy.

In this study, Bujold and team recruited 7,554 women who had not previously given birth to assess the accuracy of the new screening algorithm at 11–14 weeks of pregnancy. They tested the ability of the algorithm to predict preterm preeclampsia (preeclampsia with delivery before 37 weeks of gestation) and early-onset preeclampsia (preeclampsia with delivery before 34 weeks of gestation).

The algorithm detected 63.1% of preterm preeclampsia and 77.3% of early-onset preeclampsia cases, with a 15.8% rate of false positives, which is more accurate than the standard American College of Obstetricians and Gynecologists equivalent test rates, which the researchers estimated at 61.5% and 59.1%, respectively, and a 34.3% false positive rate.

“Using this new screening model, treatment decisions were based on each individual’s personal risk,” Bujold explained in a press statement.

“With their personal risk calculated, it’s much easier for a woman to make the right decision, for example, if she chooses to take daily low-dose aspirin, she is much more likely to follow through because it’s based on personalized screening test.”

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