Incidence of postpartum depression in Olmsted County, Minnesota. A population-based, retrospective study

To provide population-based data on the recognition of postpartum depression by reviewing diagnostic and treatment practices of all physicians caring for pregnant and postpartum women in Olmsted County, Minnesota.

We reviewed the medical charts of a random sample of 403 Olmsted County women who gave birth in 1993. Using outpatient and hospital medical records, we recorded all documented symptoms and diagnoses of depression, drug therapy for depression and variables that were previously associated with postpartum depression, during pregnancy and for one year postpartum.

Fifteen (3.7%) of the women were identified as having postpartum depression during the year following delivery. Two (0.5%) other women had preexisting depression that did not remit before delivery. We found significant associations between postpartum depression and young maternal age, single marital status, hyperemesis gravidarum, tobacco or illegal drug use during pregnancy, history of substance abuse, high utilization of emergency department services and previous affective disorder. Using multivariate analysis with stepwise logistic regression, only single marital status, previous affective disorder and high utilization of emergency services remained associated with postpartum depression.

The incidence of postpartum depression was significantly below incidences seen in prospective studies. Systematic screening for postpartum depression may be appropriate in this population.