Simple Blood Test Identifies Women in Labor at Risk for Preeclampsia

Between 5% and 10% of pregnant women develop preeclampsia, a leading cause of maternal death, characterized by sudden high blood pressure and protein in the urine. Black women are 60% more likely to develop preeclampsia compared to white women and are also more likely to experience severe outcomes, including death or kidney damage. A simple blood test may now assist doctors in identifying women in labor who are at risk for preeclampsia, enabling them to take preventive measures.

Researchers have discovered that doctors can predict a woman’s risk of developing preeclampsia by calculating the ratio of two blood proteins—fibrinogen and albumin—measured in routine blood tests conducted when women in labor arrive at the hospital. Fibrinogen plays a role in blood clotting and inflammation, while albumin is essential for maintaining fluid balance and transporting hormones, vitamins, and enzymes throughout the body. Both proteins can be disrupted in cases of preeclampsia, with fibrinogen levels potentially elevated, albumin levels reduced, or both occurring simultaneously. There is no universally recognized normal value for this fibrinogen-to-albumin ratio (FAR), which can vary from 0.05 to 1 or higher. Elevated FAR values are frequently associated with increased inflammation, infection, or serious health issues, and higher FAR readings raise greater concern. This trend has been consistently observed when using FAR to assess other inflammatory conditions, such as rheumatoid arthritis, cardiovascular diseases, and inflammatory bowel disease.

Although preeclampsia can develop as early as the 20th week of pregnancy, the study conducted by researchers at the Icahn School of Medicine at Mount Sinai (New York, NY, USA) focused on identifying women at risk for preeclampsia upon their admission to the hospital during labor. The researchers analyzed the records of 2,629 women who gave birth between 2018 and 2024, including 1,819 who did not have preeclampsia, 584 who had preeclampsia with mild features (such as blood pressure of 140/90 mm Hg or higher without significant organ damage), and 226 who presented with preeclampsia with severe features (including blood pressure of 160/110 mm Hg or higher and signs of organ damage like severe headaches, elevated liver enzymes, visual disturbances, low platelet count, or kidney impairment). The researchers found that women with a higher FAR were more likely to develop preeclampsia than those with a lower FAR.

Research presented at the ANESTHESIOLOGY 2024 annual meeting indicated that the predicted likelihood of developing any degree of preeclampsia was 24% for patients with a FAR of at least 0.1 upon hospital admission, increasing to over 41% when the FAR exceeded 0.3. If a woman in labor is found to be at elevated risk for preeclampsia based on the FAR and other clinical indicators—such as being older than 35, having chronic high blood pressure, or being obese—obstetricians and anesthesiologists can implement additional precautions to minimize risk and ensure stable blood pressure and fluid levels. For instance, they may order more frequent blood pressure monitoring or laboratory tests. If the FAR suggests that a woman is at risk for severe symptoms of preeclampsia, an epidural for pain management can be administered early to mitigate potential risks.

“While FAR has been associated with other inflammatory conditions, its specific application to preeclampsia and preeclampsia with severe symptoms has not been reported in a group this large and racially diverse,” said Lucy Shang, B.A., lead author of the study and a medical student at the Icahn School of Medicine at Mount Sinai. “Our study shows that FAR can be a predictive tool that gives anesthesiologists and obstetricians a new method for assessing a laboring mom’s risk of developing preeclampsia when they are admitted to the hospital.”