Men with inflammatory bowel disease (IBD) have a slightly reduced fertility, and this is observed in both ulcerative colitis and Crohn’s disease, as reported in a study.
The study evaluated fertility in a national cohort of 29,104 men with IBD aged 15–44 years identified from the Swedish National Patient Register and 140,901 healthy individuals who were matched based on age and place of residence.
Researchers obtained information about childbirths from the Swedish Multi-Generation Register. They classified patients with indeterminate colitis or inconsistent IBD as IBD-unclassified (IBD-U).
Compared with the reference cohort, IBD patients had a lower fertility rate. The corresponding number of births were 1.28 vs 1.35 per 1,000 person years (p<0.001).
Of note, fertility was somewhat impaired across all IBD subtypes, namely ulcerative colitis (hazard ratio [HR], 0.93, 95 percent confidence interval [CI], 0.91–0.96), Crohn's disease (HR, 0.95, 95 percent CI, 0.92–0.98), and IBD-U (HR, 0.92, 95 percent CI, 0.89–0.95).
Men in all IBD subgroups also showed a lower cumulative total parity and the parity progression compared with the comparison cohort. Within the IBD cohort disease severity, men with intensity of medical treatment (Crohn’s disease) and bowel surgery (IBD-U) showed further decreased fertility rates.
The findings add new evidence on the impact of IBD on male fertility.