# Periconceptional antibiotic use and early- to mid-pregnancy psychological distress in a nationwide birth cohort: cross-sectional analysis from the Japan Environment and Children’s Study

## TL;DR

This study explores how antibiotic use before and during early pregnancy may be linked to psychological distress in expectant mothers in Japan.

## Contribution

The study identifies a potential link between periconceptional antibiotic use and increased psychological distress during early to mid-pregnancy.

## Key findings

- Antibiotic use during either period before or after pregnancy recognition was associated with a slight increase in moderate psychological distress.
- Use during both periods was linked to a higher risk of both moderate and severe psychological distress.
- A dose-response pattern suggests even limited antibiotic use may independently contribute to psychological distress.

## Abstract

Antibiotic use has recently emerged as a potential risk factor for psychiatric disorders, but evidence regarding its risk during pregnancy remains limited, despite the frequent use of antibiotics in pregnant women. We investigated the association between antibiotic use in the year prior to early pregnancy and psychological distress during early- to mid-pregnancy.

Participants were 94,490 expectant mothers from the Japan Environment and Children’s Study, an ongoing nationwide birth cohort study. Antibiotic use during the year before early pregnancy was categorized as follows: (1) no use, (2) use during either the period before or after pregnancy recognition, and (3) use during both periods. Psychological distress was measured during early- to mid-pregnancy using the Kessler Psychological Distress Scale, with scores of 5–12 and ≥ 13 indicating moderate and severe psychological distress, respectively. A Bayesian multinomial generalized linear model was used to calculate adjusted odds ratios (aORs) and 95% credible intervals (95% CrIs), controlling for a priori selected potential confounders.

Analysis using no antibiotic use as a reference revealed that the aORs (95% CrIs) for moderate psychological distress were 1.07 (0.97–1.19) for use during either period and 1.22 (1.08–1.38) for use during both periods. For severe psychological distress, the aORs (95% CrIs) were 1.07 (0.97–1.19) and 1.50 (1.15–1.94), respectively.

A dose–response-like pattern was observed, suggesting that even limited antibiotic use may be an independent risk factor for psychological distress during early- to mid-pregnancy, highlighting the importance of judicious antibiotic use from the preconception period.

The online version contains supplementary material available at 10.1186/s12889-025-26119-0.