An association between antibiotic usage during pregnancy and the subsequent development of autoimmune hepatitis

Whether the incidence of autoimmune hepatitis (AIH) is higher in women prescribed antibiotics during pregnancy remains to be determined.

Administrative databases and hospital abstracts were reviewed to identify all pregnant women in the province of Manitoba from 1996 to 2001 who were prescribed antibiotics during pregnancy and subsequently diagnosed with AIH until 2020.

In this study, 70,666 pregnant women were identified during the 5-year period. Antibiotics were prescribed in 11,654 (16.5%). AIH was subsequently diagnosed in more mothers who were prescribed antibiotics than in those who were not (82/11,654 [0.7%] versus 166/58,975 [0.28%], p <0.0001). The number of antibiotic prescriptions was higher in mothers who subsequently developed AIH than in those who were prescribed antibiotics but did not develop AIH (0.56 [SD 1.09] versus 0.24 [SD 0.67], p <0.0001) as were the prescribed durations of treatment (4.19 [SD 7.72] versus 2.03 [SD 7.55] days, p <0.0001). The mean ages (25.9 [SD 6.0] and 26.8 [SD 5.8]; years) and times to AIH diagnosis (10.6 [SD 4.9] and 10.8 [SD 4.8] years) were similar in mothers who were prescribed and not prescribed antibiotics and developed AIH. The relative risk of developing AIH in antibiotic recipients was 2.5 (95% CI 1.92-3.25, p <0.0001), and the hazard ratio was 2.58 (95% CI 1.98-3.36, p <0.001).

These results describe an association between mothers prescribed antibiotics during pregnancy and the subsequent development of AIH.