Women who experience high levels of stress during pregnancy are more likely to develop postpartum depression, but strong social support networks can ease those stresses and reduce the risk of mental-health issues after delivery, new research shows.
 

The study, published in the journal Clinical Psychological Science, found expectant mothers who get a lot of support from their families are protected from sharp increases in a particular stress hormone, making them less likely to develop postpartum depression.
 

"Now we have some clue as to how support might 'get under the skin' in pregnancy, dampening down a mother's stress hormone, and thereby helping to reduce her risk for postpartum depression," said lead researcher Jennifer Hahn-Holbrook, with the University of California-Los Angeles National Institute of Mental Health.
 

For the study, scientists surveyed 210 pregnant women about their social support and symptoms of depression three times during pregnancy — at 19, 29, and 37 weeks — and eight weeks after giving birth. In addition, the women’s blood was analyzed to assess levels of placental corticotropin-releasing hormone (pCRH), a stress hormone released from the placenta tied to postpartum depression.
 

The results showed pregnant women who reported the greatest support from their families had relatively lower levels of depressive symptoms and smaller increases in pCRH during pregnancy.
 

"Our results, and those of other scientists, suggest that low or absent support is a significant risk factor for postpartum depression, and that strong support is a protective factor," Hahn-Holbrook said.
 

The study was funded, in part, by the National Institute of Child Health and Human Development, a part of the National Institutes of Health.