Events Within the First Year of Life, but Not the Neonatal Period, Affect Risk for Later Development of Inflammatory Bowel Diseases.

BACKGROUND & AIMS: We performed a population-based study to determine whether there was an increased risk of inflammatory bowel diseases (IBD) in persons with critical events at birth and within 1 year of age.

METHODS: We collected data from the University of Manitoba IBD Epidemiology Database, which contains records on all Manitobans diagnosed with IBD from 1984 through 2010 and matched controls. From 1970 individuals' records can be linked with those of their mothers, so we were able to identify siblings. All health care visits or hospitalizations during the neonatal and postnatal periods were available from 1970 through 2010. We collected data on infections, gastrointestinal illnesses, failure to thrive, and hospital readmission in the first year of life and sociodemographic factors at birth. From 1979, data were available on gestational age, Apgar score, neonatal admission to the intensive care unit, and birth weight. We compared incident rate of infections, gastrointestinal illnesses, and failure to thrive between IBD cases and matched controls as well as between IBD cases and siblings.

RESULTS: Data on 825 IBD cases and 5999 matched controls were available from 1979. Maternal diagnosis of IBD was the greatest risk factor for IBD in offspring (odds ratio [OR], 4.53; 95% confidence interval [CI], 3.08-6.67). When we assessed neonatal events, only being in the highest vs lowest socioeconomic quintile increased risk for later development of IBD (OR, 1.35; 95% CI, 1.01-1.79). For events within the first year of life, being in the highest socioeconomic quintile at birth and infections (OR, 1.39; 95% CI, 1.09-1.79) increased risk for developing IBD at any age. Infection in the first year of life was associated with diagnosis of IBD before age 10 years (OR, 3.06; 95% CI, 1.07-8.78) and before age 20 years (OR, 1.63; 95% CI, 1.18-2.24). Risk for IBD was not affected by gastrointestinal infections, gastrointestinal disease, or abdominal pain in the first year of life.

CONCLUSIONS: In a population-based study, we found infection within the first year of life to be associated with a diagnosis of IBD. This might be due to use of antibiotics or a physiologic defect at a critical age for gut microbiome development.