A Blood Test to Predict Postpartum Depression?

Genetic markers could help doctors identify women at high risk

About one in seven women experience postpartum depression (PPD), making it one of the most common pregnancy complications. Yet few women are screened for this debilitating and treatable condition, and researchers in England are hoping a blood test changes that. Identifying women at high risk for the condition during pregnancy could make it possible for them to get the care they need to prevent postpartum depression.

A team from the University of Warwick followed 140 women at University Hospitals Coventry and Warwickshire in the United Kingdom starting in their second or third trimester of pregnancy through two months after delivery. They found a specific genetic marker in the women's blood that was associated with an increased risk of developing PPD.

Although research is still in the early stages, experts hope that eventually doctors will be able to use a simple blood test to screen women for PPD before they develop the condition. "The ideal would be to use a genetic screening as a first-line test so you can focus your attention on these women who are more at risk," says Dimitris Grammatopoulos, professor of molecular medicine at the Warwick Medical School at the University of Warwick and lead author of the study, which was published online in the Journal of Psychiatric Research

"If we can identify women at high risk early enough, we may be able to put measures in place to prevent development of the disease, for example exercising and strengthening support from family and friends," Grammatopoulos says. And even if it's not possible to prevent postpartum depression, women at high risk could at least know the warning signs and get help earlier.

Based on a 10-question survey, the study found that 20 percent of the women studied were at high risk for depression between 20 and 28 weeks of pregnancy. A second survey found that 24 percent were at high risk for depression between two and eight weeks after delivery.

Researchers then studied whether women were more likely to be at high risk for depression if they had variations in two genes that help regulate the body's response to hormones, especially estrogen (which is high during pregnancy and then drops after delivery).

Women with a specific variation in one of the genes were about three times more likely to be at high risk for PPD between two and eight weeks after delivery. A variation in the other gene was associated with a fivefold increased risk of PPD, as well as increased risk of depression during pregnancy.

Some experts caution that a blood test would have to be very accurate before doctors could use it to predict who will develop depression and decide which women need treatment. "You don't want women to panic, so you have to have very good predictive value," says Kimberly Yonkers, MD, a professor of obstetrics, gynecology, and reproductive sciences at the Yale School of Public Health. "We are just not there yet."

Grammatopoulos and his colleagues are currently testing whether the two genetic variations they found can predict the risk of depression during and after pregnancy in a much larger study of about 10,000 women. The study could take about two years to complete.

But even if the test proves highly predictive, Yonkers sees access to treatment as the real obstacle. "The problem isn't discerning whether somebody has depression or psychological distress, the problem is getting them treatment [because] they don't have [adequate] insurance or don't prioritize treatment."

If you think you may have postpartum depression, answer these simple screening questions