On Feb. 12, 2025, a study led by researchers from the University of Washington announced that a new blood test has an 80% accuracy in predicting preterm preeclampsia, according to their findings published in the journal Nature Medicine.  

The condition, which results in over 70,000 maternal deaths and 500,000 fetal deaths each year worldwide, has long been hard to predict. Preeclampsia is a pregnancy complication characterized by high blood pressure (hypertension) or organ dysfunction. It typically occurs in the third trimester. The condition’s exact cause is unknown, but doctors suspect it is related to an abnormal interaction between the placenta and the mother’s blood vessels.  

Researchers have known for at least two decades that the placenta sheds DNA into maternal blood. Labs have been able to extract cell-free DNA, sequence it and use the sample to screen for fetal abnormalities such as Down syndrome. UW Medicine and Fred Hutch Cancer Center teams collaborated in developing the idea to use cell-free DNA sequence data to screen for pre-eclampsia, Dr. Swati Shree, a UW Medicine OB-GYN and co-corresponding author of the paper, said.

The researchers found that their approach, which uses signals stored within circulating cell-free DNA sequence data, had 80% sensitivity at predicting whether a pregnant individual would experience preterm preeclampsia or not.

The next steps would be to improve the training model with more samples, and ultimately to conduct a trial that includes thousands of patients. The researchers hope a test like this could become an early preeclampsia prediction tool that seamlessly integrates into routine early pregnancy screening.