Maternal pain during pregnancy dose-dependently predicts postpartum depression: The Japan Environment and Children's...

Postpartum depression (PPD) affects women during the first year after delivery. This study investigated the association between prenatal pain (maternal pain during pregnancy) and PPD.

Data were analyzed from the Japan Environment and Children's Study (JECS), a nationwide prospective birth cohort study. Information on prenatal pain was collected twice during pregnancy through self-administered questionnaires. PPD symptoms were assessed using the Edinburgh Postnatal Depression Scale at one month postpartum. Poisson regression analyses were performed to investigate the association between prenatal pain and PPD, with other putative risk factors adjusted in the model.

Among 84,801 study subjects, 11,535 (13.6%) were screened as positive for PPD. In the present study, the occurrence of prenatal pain was 69.6 and 84.0% at the first trimester and the second/third trimester, respectively. A positive relationship between any degree of pain and PPD in both the first and the second/third trimester was observed. A significant linear dose-dependent association was also found (Ptrend < 0.001) when the subjects were divided by the severity of pain. Using participants without any pain at either point as a reference, those with persistent pain both at the first and the second/third trimesters showed the highest risk for PPD: aRR = 1.95 (95%CI: 1.76-2.15; p < 0.001).

No detailed information regarding the type or site of prenatal pain was available in the JECS questionnaires, neither did data concerning delivery and postpartum pain.

The study results suggest that prenatal pain is a dose-dependent risk factor for the development of PPD.