Reduced Fertility Rate in Female with Crohn's Disease: A Population-Based Cohort Study in China

Backgroud: This study aims to clarify the uncertain impact of Crohn’s disease on fertility among Chinese female by comparing their fertility rates with those of the general female population. Methods From January 2012 to December 2022, Crohn’s disease patients at Sixth Affiliated Hospital of Sun Yat-sen University were identified through hospital records. Female patients aged 15 to 44 were included. Demographic and fertility data were collected through structured questionnaires. Comparative data for the general population aged 15 to 44 were obtained from the National Bureau of Statistics of China. Age-adjusted overall fertility rate and adjusted fertility rate ratio (AFRR) were calculated using poisson regression, along with fertility rate ratios for 5-year age groups stratified by disease onset, surgery, and perianal disease. Results A total of 564 valid questionnaires were collected. The overall fertility rate among females with Crohn’s disease was 43.41 live births per 1000 person-years (95%CI [39.30-48.11.]), significantly lower than the general population(52.80, 95%CI[52.72–52.97], AFRR 0.82, p < 0.001). Pre-onset rates showed no significant difference, but there was a significantly decline post-onset(35.84, 95%CI[30.32–42.31], AFRR 0.55, 95%CI[0.46–0.65], p < 0.001). Fertility rates decreased in patients aged 20 to 29 post-onset. Those who underwent bowel surgery had reduced fertility rates post-surgery(31.44, 95%CI[21.05–92.49] vs 49.92, 95% CI [45.35–54.91], AFRR 0.63, 95% CI [0.45–0.89], p = 0.008). Patients with perianal disease was 47% of that of the general population (25.05, 95% CI [8.94–40.97] vs. 48.61, 95% CI [43.57–52.97], AFRR 0.47, 95% CI [0.43–0.52], p < 0.001). Conclusion Female Crohn's disease patients show lower fertility rates than the general population, particularly among those aged 20–29 age post-disease onset, with further reductions after surgery and perianal disease.