Postpartum depression affected 12%–20% of mothers surveyed in the most recent report from the Centers for Disease Control and Prevention's Pregnancy Risk Assessment Monitoring System (PRAMS).
These proportions are somewhat higher than the 10%–15% of mothers generally thought to be affected by postpartum depression within 1 year of giving birth, Kate Brett, Ph.D., and associates in the Office of Analysis and Epidemiology, National Center for Health Statistics.
PRAMS is an ongoing population-based surveillance project that collects data on mothers' attitudes and experiences before, during, and after delivery of a live infant. It targets subjects who are representative of women who have recently delivered in 17 participating states.
In an analysis of the data collected in 2004–2005—the most recent period for which data were available—Dr. Brett and her colleagues found that four characteristics were significantly associated with postpartum depression in all 17 states: young maternal age, low levels of maternal education, single marital status, and Medicaid coverage for delivery.
Five potential risk factors also were associated with postpartum depression: maternal tobacco use during the last trimester, physical abuse before or during the pregnancy, partner-related stress during the pregnancy, traumatic stress during the pregnancy, and financial stress during the pregnancy.
In addition, delivering a low-birth-weight infant was significantly associated with postpartum depression in 14 states.
In the current survey, 11.8% of new mothers in Maine and 11.8% in Vermont reported postpartum depression, compared with about 20.4% of mothers in New Mexico. Oregon and Minneapolis were also clustered in the lower ranges, with 12.2%, and 12.7%, respectively, of new mothers reporting symptoms, whereas in South Carolina and North Carolina, 19.5% and 19.0%, respectively, reported symptoms.
The associations with young maternal age and partner-related stress or physical abuse have been reported in previous research. In contrast, the associations with low-birth-weight infants, tobacco use during pregnancy, and traumatic or financial stress have not been identified before, the investigators said (MMWR 2008;57:361-6).
These findings can be used to tailor screening and interventions so that they target mothers at highest risk for postpartum depression. For example, “adolescent mothers or women who received Medicaid for their delivery are examples of subsets of the population” who can be easily identified at delivery and referred for treatment, the CDC said.