Colon to Rectum
Gut. 2025;74(2):206-213
Impact of prenatal and postnatal maternal IBD status on offspring’s risk of IBD: A population-based cohort study
Objective: In utero exposure to maternal inflammation may impact immune system development and subsequent risk of disease. The authors investigated whether a maternal diagnosis of inflammatory bowel disease (IBD) before childbirth is linked to a higher risk of IBD in offspring compared with a diagnosis after childbirth. Further, they analysed paternal IBD status for comparison.
Design: Using Danish health registers, the authors identified all individuals born in Denmark between 1997 and 2022 and their legal parents, as well as their IBD status. Cox proportional hazards regression analyses adjusted for calendar period and mode of delivery were used to estimate offspring IBD risk by maternal and paternal IBD status before and after childbirth.
Results: Of 1,290,358 children, 10,041 (0.8%) had mothers with IBD diagnosis before childbirth and 9985 (0.8%) had mothers with IBD diagnosis after childbirth. Over 18,370,420 person-years, 3537 individuals were diagnosed with IBD. Offspring of mothers with IBD before childbirth had an adjusted hazard ratio (aHR) of IBD of 6.27 (95% confidence interval [CI]: 5.21–7.54) compared with those without maternal IBD, while offspring of mothers with IBD after childbirth had an aHR of 3.88 (95% CI: 3.27–4.60). Corresponding aHRs were 5.26 (95% CI: 4.22–6.56) among offspring with paternal IBD before childbirth and 3.73 (95% CI: 3.10–4.50) for paternal IBD after childbirth.
Conclusion: Offspring had a greater risk of inflammatory bowel disease (IBD) when either parent was diagnosed before childbirth rather than later, emphasising genetic predisposition and environmental risk factors rather than maternal inflammation in utero as risk factors for IBD.