Age-specific 3-month cumulative incidence of postpartum depression: The Hamamatsu Birth Cohort (HBC) Study

BackgroundThe prevalence of postpartum depression (PPD) in the general population has been reported to be 10% to 15% worldwide. However, the relevance of age of the parturients to the emergence of PPD has not been well documented. To address this, we estimated the age-specific 3-month cumulative incidence of PPD using the Hamamatsu Birth Cohort for Mothers and Children (HBC).MethodsWomen with PPD were defined as those scoring 9 points or higher using the Edinburgh Postnatal Depression Scale 3 months after childbirth.ResultsAmong 675 participating parturients, 100 women were found to have PPD; the cumulative incidence of PPD over the 3 months after childbirth was 14.8%. The age-specific estimates were 20.8% for < 25 years, 14.2% for 25 to 29 years, 11.5% for 30 to 34 years, and 17.9% for ≥ 35 years. In the logistic regression analysis, the increased OR for having PPD among parturients aged ≥ 35 years was 1.7, which remained significant after controlling for age of partner, parity, and household income.LimitationsAlthough the sample was representative, the sample size was modest.ConclusionThe cumulative incidence of PPD was significantly different across age groups, with the highest estimates in the advanced age band. The heightened estimate was not accounted for by the age of the partner, parity, or annual household income.