New blood test accurately predicts preeclampsia, reports research

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.

Earlier, this testing was shipped to outside labs for processing, but in 2017, UW Medicine started doing these tests in house, one of the first healthcare systems to do so, Shree added.

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, Shree said.

Over the past two years, the investigators, led by Shree and co-corresponding author Gavin Ha, a computational biologist at Fred Hutch, used this data, which functions as a liquid biopsy, from the first trimester of pregnancy for over 1,000 pregnant individuals to develop and then validate their test.

“The innovation in this tool reinforces how important it is. Liquid biopsy tests were pioneered in pregnancy health research and is now an emerging research area in oncology,” said Ha. “There are similarities in the genes we’re looking at in both areas of research, which makes this study a collaboration which bridges both fields.”

The samples were collected between 2017-2023. 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.

Shree said that 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.

“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,” she said. 

Reference:

Adil, M., Kolarova, T.R., Doebley, AL. et al. Preeclampsia risk prediction from prenatal cell-free DNA screening. Nat Med (2025). https://doi.org/10.1038/s41591-025-03509-w