Effects of Selective Serotonin Reuptake Inhibitors and Ondansetron on Urinary Tract Infections in Pregnancy

Urinary tract infections (UTIs) are prevalent during pregnancy and pose risks of adverse outcomes. Recent research suggests that urethral serotonin signaling may protect against ascending uropathogens. With the common use of Selective Serotonin Reuptake Inhibitors (SSRIs) and ondansetron, a serotonin receptor antagonist, during pregnancy, it is essential to explore their interactions with serotonin mechanisms to improve maternal health care. This study examines the relationship between SSRIs and ondansetron use in pregnancy and the incidence of UTIs and other negative outcomes. A retrospective analysis of data from 7,023 pregnant women in the PeriBank database (IRB ID: 2023-0263), from February 2020 to April 2023, revealed that 1,019 received ondansetron and 316 were on SSRIs, including fluoxetine, sertraline, escitalopram, and citalopram. An experimental component involving pregnant mice treated with ondansetron or saline before E. coli infection further assessed UTI severity. Findings indicated that pregnant women using ondansetron had significantly increased odds of developing UTIs, while no significant association was noted for those on SSRIs. Additionally, pregnant mice administered ondansetron exhibited more severe bladder infections compared to those given saline. These results suggest SSRIs are not linked to an increased UTI risk or adverse outcomes, whereas ondansetron is associated with higher UTI risk and pre-term birth. Thus, careful use of ondansetron during pregnancy is recommended to avoid potential risks to maternal and fetal health.