Pediatric IBD Associated With Antibiotic Exposure Before Age 2 Years

Children exposed to antibiotics prior to age 2 years were more likely to develop Crohn disease, but no significant association was found for pediatric ulcerative colitis.

Antibiotic exposure in children before age 2 years is associated with an increased risk for pediatric inflammatory bowel disease (PIBD) before age 18 years, according to study results presented at the Advances in Inflammatory Bowel Diseases (AIBD) 2022 conference, held from December 5 to 7, 2022, in Orlando, Florida.

Investigators sought to determine if antibiotic exposure before birth and during the first 2 years of life — prior to a fully developed gut microbiome — were independently associated with subsequent PIBD.

Using data from the Norwegian Patient Registry, researchers identified children with PIBD aged younger than 18 years who were born between 2004 and 2012. Data regarding dispensed antibiotics were obtained from the Norwegian Prescription Database, and data on potential confounding factors were from the Medical Birth Registry of Norway and Statistics Norway. The participants were followed through December 31, 2020.

A total of 536,821 children were included in the register-based cohort study, of whom 758 had PIBD (Crohn disease [CD], 53%; ulcerative colitis, 32%; and IBD unclassified, 15%).

This association was found for CD only and was robust to adjustments for prenatal antibiotic exposures and other potential confounders.

The adjusted odds ratio (aOR) after adjustment for sex of IBD occurring in participants exposed to antibiotics before age 2 years vs no exposure was 1.40 (95% CI, 1.21-1.61). The aOR was 1.39 (95% CI, 1.20-1.59) after adjustment for prenatal antibiotic exposure. Additional adjustments for potential confounders, including mode of delivery, preeclampsia, birthweight and gestational age, season of birth and maternal age, education, smoking, and parity did not affect the OR estimates by more than ±0.01.

The strongest association occurred in children exposed to at least 2 courses of antibiotics (aOR, 2.14; 95% CI, 1.34-3.43) and for broad-spectrum antibiotics (aOR, 2.36; 95% CI, 1.45-3.83) vs those who had no exposure. This association was largely accounted for by children with CD (aOR, 1.59; 95% CI, 1.31-1.94; P <.01). No significant association with antibiotics was found in children with UC (aOR, 1.12; 95% CI, 0.87-1.44; P =.89).

Antibiotic exposure in the last trimester was associated with PIBD (aOR, 1.23; 95% CI, 1.01-1.51), although it was borderline significant after adjustment for postnatal antibiotic use (P =.07).

“Children exposed to antibiotics before 2 years of age were 1.4-fold more likely to develop IBD before age 18 years than controls,” the study authors noted. “This association was found for CD only and was robust to adjustments for prenatal antibiotic exposures and other potential confounders.”


Andersen S, Hestetun S, Bernklev T, et al. Antibiotic exposure before two years of age is associated with increased risk of pediatric IBD in a Norwegian nation-wide study. Abstract presented at: AIBD 2022; December 5-7, 2022; Orlando, FL. Abstract 124.