Association Between Antibiotic Exposure During Pregnancy and Postpartum Depressive Symptoms: The Japan Environment and Children's Study.

Antibiotic exposure was self-reported and did not specify type, timing, or duration. The reason for antibiotic use and the infection itself were not recorded, so the infection itself may matter. Psychological distress was measured only once, so its causal position cannot be established. The gut microbiota was not measured, so the proposed mechanism was not tested. The analysed sample was smaller than the original cohort because many mothers were excluded for missing data, cesarean section, or psychiatric history. No data on previous stress, depression, or family history of depression were collected.

The authors declared no conflicts of interest. The underlying JECS cohort was government funded by the Ministry of the Environment of Japan.

Do not conclude that antibiotics in pregnancy cause postpartum depression. The adjusted association was not significant, and the path analysis only showed an indirect link through distress, which cannot prove cause.