Antibiotic or gastric acid inhibitor use during pregnancy and postpartum depression: Population-based cohort study.

Introduction: Postpartum depression is one of the most common non-obstetric postnatal complications. As the microbiome (and gut-brain axis) as well as inflammation may be involved in the mechanism, we aimed to assess if antibiotic or gastric acid inhibition use during pregnancy affects the risk of postpartum depression (clinical diagnosis and/or antidepressant use up to 1 year after childbirth).

Material And Methods: This population-based cohort study used first singleton pregnancy resulting in a live birth in Sweden from 2006 to 2016. Women with history of depression were excluded. Multivariable logistic regression models were used to assess the impact of antibiotics and gastric acid inhibitors and other risk factors, presented as odds ratios (ORs) with 95% confidence intervals (CI).

Results: Overall, 29% of all 10 666 women with postpartum depression were exposed to antibiotics and 6.2% to gastric acid inhibitors, compared to, respectively, 21% and 3.2% of 613 205 women without postpartum depression. Antibiotic use during pregnancy was associated with postpartum depression (OR 1.43, 95% CI 1.37-1.49), particularly for quinolones and other antibacterials (including nitroimidazole derivatives). Gastric acid inhibition was associated with an even higher risk than antibiotics (OR 2.04, 95% CI 1.88-2.21). Both antibiotics and gastric acid inhibitors suggested higher risk with increased dose in a dose-response analysis.

Conclusions: The use of antibiotics and gastric acid inhibition drugs during pregnancy appeared to be associated with a higher risk of postpartum depression. However, it is important to consider that other predisposing factors could contribute to this increased risk, even after excluding individuals with a history of depression.