A simple blood test could help doctors identify women in labour who are at the risk for preeclampsia — a leading cause of maternal death.

Between 5 to 10 per cent of pregnant women develop preeclampsia (sudden high blood pressure and protein in the urine), according to the Centers for Disease Control and Prevention (CDC).

While preeclampsia can develop as early as the 20th week of pregnancy, the study focused on identifying women who were at risk for preeclampsia when they were admitted to the hospital in labour.

Researchers have determined 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 done when women in labour enter the hospital.

Fibrinogen is involved in blood clotting and inflammation, while albumin helps maintain fluid balance and carries hormones, vitamins and enzymes throughout the body.

Both can be disrupted with preeclampsia — fibrinogen may be elevated, albumin may be reduced, or both can occur.

There is no universally established normal value for this fibrinogen-to-albumin ratio (FAR), which can range from 0.05 to 1 or higher. Higher FAR values are often associated with increased inflammation, infection or serious health conditions, and the higher the FAR, the greater the concern.

In the study, researchers analysed the records of 2,629 women who gave birth between 2018 and 2024, 1,819 who did not have preeclampsia, 584 who had preeclampsia with mild features or symptoms and 226 who had preeclampsia with severe features or symptoms.

The researchers determined those who had a higher FAR were more likely to develop preeclampsia than those with a lower FAR.

They found that the predicted likelihood of developing any degree of preeclampsia was 24 per cent for patients with a FAR of at least 0.1 on admission to the hospital, and it rose to more than 41 per cent when that value was above 0.3.

If a woman in labour is found to be at increased risk for preeclampsia based on the FAR and other clinical indicators — such as being older than 35 or having chronic high blood pressure or obesity — obstetricians and anaesthesiologists can take extra precautions to reduce the risk and ensure the patient’s blood pressure and fluid levels remain stable and controlled.

“For example, they can order more frequent blood pressure checks or lab tests. If the FAR indicates a woman is at risk for preeclampsia with severe symptoms, an epidural for pain management can be placed early before it becomes too risky,” the authors suggested.

“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 lead author of the study from the Icahn School of Medicine at Mount Sinai, New York.