Preeclampsia is a complication that arises in five to eight percent of pregnancies. It causes high blood pressure (hypertension) and may also cause premature birth, organ dysfunction. It can also increase the risk of stroke or seizure. Preeclampsia is thought to lead to an estimated 500,000 fetal and 70,000 maternal deaths around the world every year.
Preeclampsia usually happens in the third trimester of pregnancy, and it's thought to be related to abnormalities in how the placenta interacts with maternal blood vessels. It can be difficult for clinicians to know who may develop the condition, making it harder to prevent or treat. But scientists have now developed a blood test that can predict preeclampsia with 80 percent accuracy. This test may help healthcare providers treat the condition before it causes serious problems. The work has been reported in Nature Medicine.
"The placenta is not something we can biopsy during pregnancy, but we believe it is integral to developing preeclampsia," noted co-corresponding study author Dr. Swati Shree, a University of Washington Medicine OB-GYN. "Doctors do look at clinical risk factors, which can work reasonably well, but it still misses a fair amount of people."
Molecules like DNA can shed from the placenta into maternal blood, and move into circulation. This cell-free placental DNA can be identified in maternal blood samples, and has been used to identify fetal abnormalities. Scientists wanted to find a way to use these samples to identify pregnancies where preeclampsia was likely to arise.
The researchers assessed samples from more than 1,000 pregnant individuals between 2017 and 2023 to create and validate this test. It was found to be 80 percent sensitive at predicting who would get preeclampsia.
Now, the researchers want to obtain more samples so they can validate the test in more people. It may eventually become a common screening tool that could save lives.
"Although using liquid biopsies for human diseases is largely used in the cancer area, given the frequency at which cell-free DNA screening is performed, prenatal biology truly has incredible opportunities for the discovery and application of innovative tools," said Shree.
Sources: University of Washington School of Medicine, Nature Medicine
