A large nationwide study from South Korea has found no strong evidence that taking antibiotics during pregnancy or in a child’s first year of life increases the overall risk of autoimmune diseases in children. The findings, published this week in PLoS Medicine, may offer reassurance to both healthcare providers and parents concerned about the long-term effects of antibiotic use during these sensitive periods.
Antibiotics are among the most commonly prescribed medications worldwide and play a vital role in treating bacterial infections. Because they target bacterial structures and processes not found in human cells, they can effectively kill or suppress bacteria without directly harming human tissues. Yet concerns have lingered that disrupting the infant microbiome during early immune development might raise the risk of chronic immune-related diseases later in life.
Korean researchers analyzed health insurance data from more than 3 million mother-child pairs, covering births between 2008 and 2021. They looked specifically at whether exposure to antibiotics, either in the womb or during infancy, was linked to conditions such as type 1 diabetes, juvenile idiopathic arthritis, inflammatory bowel disease, systemic lupus erythematosus, or Hashimoto’s thyroiditis. Using advanced statistical methods, including sibling-matched analyses to reduce confounding, the study found no significant association between early antibiotic exposure and the overall risk of autoimmune disease.
Among 2.7 million children exposed to antibiotics before birth, risk estimates for autoimmune diseases such as type 1 diabetes, juvenile idiopathic arthritis, and Crohn’s disease were not statistically significant. In over 3.3 million children, antibiotic use during the first year of life similarly showed no meaningful increase in risk. For example, the risk of type 1 diabetes remained essentially unchanged.
While the overall results were reassuring, the researchers noted a few exceptions. Maternal use of cephalosporins during the first or second trimester showed a slight increase in Crohn’s disease risk. Infants given antibiotics during the first two months of life—particularly boys—had a modestly higher risk of developing autoimmune thyroiditis. These findings echo earlier European research that found no broad link between antibiotic use and autoimmune diseases but did highlight possible risks with broad-spectrum antibiotics in specific conditions such as juvenile idiopathic arthritis.
The Korean research team emphasized that the overall risk from early antibiotic use remains low. They concluded that when medically indicated, antibiotic use during pregnancy or infancy does not appear to cause widespread harm in terms of autoimmune disease development. However, they noted that continued research is needed to clarify whether certain drugs, timing, or subgroups of patients may carry higher risks.
The study helps ease concerns that necessary antibiotic treatments might trigger long-term autoimmune complications in children. At the same time, it highlights the importance of using antibiotics judiciously, reserving them for clear medical indications while continuing to monitor potential long-term effects.
References
- Choi, E.-Y., Bea, S., Lee, H., Choi, A., Han, J. Y., Kang, E. H., & Shin, J.-Y. (2025) Exposure to antibiotics during pregnancy or early infancy and the risk of autoimmune disease in children: A nationwide cohort study in Korea. PLoS Medicine, 22(8).
- Halawa EM, Fadel M, Al-Rabia MW, Behairy A, Nouh NA, Abdo M, Olga R, Fericean L, Atwa AM, El-Nablaway M, Abdeen A. Antibiotic action and resistance: updated review of mechanisms, spread, influencing factors, and alternative approaches for combating resistance. Front Pharmacol. 2024 Jan 12;14:1305294.
- Räisänen, L.K., Kääriäinen, S.E., Sund, R. et al. Antibiotic exposures and the development of pediatric autoimmune diseases: a register-based case–control study. Pediatr Res 93, 1096–1104 (2023).