Fertility is lower in women with inflammatory bowel disease (IBD), according to a study published online Sept. 19 in the Journal of Crohn’s and Colitis.
Emma Druvefors, from County Hospital Ryhov in Jönköping, Sweden, and colleagues used the Swedish National Patient Register to identify 27,331 women with IBD (aged 15 to 44 years in 1964 to 2014) to assess differences in fertility compared to 131,892 matched individuals without IBD.
The researchers found that the fertility rate in women with IBD was 1.52 births per 1,000 person-years versus 1.62 in unaffected individuals. In all IBD subtypes, fertility was impaired (hazard ratios: Crohn disease [CD], 0.88; IBD-unclassified [IBD-U], 0.86; ulcerative colitis [UC], 0.96). During the study period, fertility improved, except among women with CD. The proportion of women with IBD progressing from one parity to the next versus the matched cohort was lower at all parity levels for CD and IBD-U. In women with CD, disease severity, bowel resections, and perianal disease affected fertility negatively.
“The increased use of contraceptives and reduced parity progression at higher parities in UC suggest that an element of voluntarily reduced fertility is involved,” the authors write. “Encouragingly, the impact of IBD on female fertility compared to healthy individuals has become less pronounced during the study period.”