“The size of this study, in over 1 million new mothers, make the findings highly significant and definitive. Most studies on postpartum depression are small and confined to a small region.
This study answers questions about risk factors for postpartum depression from a worldwide sample,” said Jennifer L. Payne, MD, the study’s senior author and director of the Reproductive Psychiatry Research Program at the UVA School of Medicine.
Postpartum Depression Risk Factors
Researchers say that the potential health effects of both mothers and children need to be included in any postpartum depression. For example, researchers point out that women are twice as likely as men to experience depression in the years after their baby is born. Women are also at risk for major depression after childbirth.
Researchers also note that children of women who experience postpartum depression are more likely to develop major depression and other psychiatric disorders. Having a mother experiencing postpartum depression is associated with developmental challenges for children, including low IQ and slow language development.
“There is a growing necessity to identify risk factors that place women at elevated risk, prior to the onset of affective illness, during this vulnerable time-period so that preventive measures can be instituted,” the researchers write.
To better understand the risk factors for postpartum depression, the researchers analyzed responses from more than 1.1 million new mothers to the “After Childbirth Survey” on the Flo app, which helps women track their period and menstrual cycle.
With age, the percentage of women who self-reported postpartum depression symptoms was higher between the ages of 18 and 24, at 10%. The rate of postpartum depression then gradually decreased with increasing age, decreasing to 6.5% in those aged 35 to 39 and slightly increasing to 6.9% in women 40 and over. Postpartum depression was significantly lower among women of all ages, compared with first-time mothers, who had previously had children.
Women who have twins are more likely to report postpartum depression, 11.3% of mothers of twins report symptoms, and 8.3% of mothers of one child. This difference is especially pronounced among mothers’ 40 years and older; 15% of mothers of this age group with twins reported postpartum depression symptoms, compared with 6.6% of mothers of one child. The researches concluded that women over the age of 40 gave birth to twins, adding that they were “markedly high risk” for postpartum depression.
The researchers found that there was no significant difference in the rates of postpartum depression between mothers of boys and girls.
“Most women with postpartum depression are not diagnosed or treated. Clinicians caring for new mothers can be aware of factors like age, first pregnancy and twin pregnancies that put women at a higher risk of developing postpartum depression and screen and intervene early,” Payne said. “Early intervention can prevent the negative outcomes associated with postpartum depression for both mothers and their children.”