University of Virginia researchers have discovered a blood biomarker that can help identify women at risk for postpartum depression.

The finding, published in the current issue of the journal Frontiers in Genetics, could pave the way for a new blood to test for the condition in pregnant women.

"We can greatly improve the outcome of this disorder with the identification of markers, biological or otherwise, that can identify women who may be at risk for its development," said Jessica Connelly, an assistant professor of psychology and senior author of the study.

"We know that women who have experienced depression before pregnancy are at higher risk of developing depression in the postpartum period. However, women who have never experienced depression also develop postpartum depression. These markers we identified may help to identify them, in advance."

Postpartum depression strikes nearly 20 percent of new mothers, putting their infants at increased risk for poor behavioral, cognitive, and social development.

Past studies involving animals have shown low levels of the hormone oxytocin — which plays a positive role in healthy birth, maternal bonding, relationships, lower stress levels, mood and emotional regulation — has been associated with postpartum depression.

The new research, which involved analyses of medical records of British women, linked genetic markers to an increased chance of a woman developing postpartum depression.

"The role of the oxytocin system in maternal behavior is well known in rodents. Our work emphasizes its importance in the human maternal condition and places the epigenetic regulation of the oxytocin receptor at the forefront," said study co-author C. Sue Carter, director of the Kinsey Institute at Indiana University.