Paradoxical Impact of Ileal Pouch-Anal Anastomosis on Male and Female Fertility in Patients With Ulcerative Colitis

Abstract

Birth rates in males with ulcerative colitis and ileal pouch-anal anastomosis have not been studied. This study aimed to estimate birth rates in males and females with ulcerative colitis and study the impact of ileal pouch-anal anastomosis. This was a retrospective registry-based cohort study that was performed over a 30-year period. Records for parenting a child from the same period were cross-linked with patient records, and birth rates were calculated using 15 through 49 years as age limits. All data were prospectively registered. All patients with ulcerative colitis and ulcerative colitis with ileal pouch-anal anastomosis between 1980 and 2010 were identified in Danish national databases. The primary outcomes measured were birth rates in females and males with ulcerative colitis and ulcerative colitis with ileal pouch-anal anastomosis. We included 27,379 patients with ulcerative colitis (12,812 males and 14,567 females); 1544 had ileal pouch-anal anastomosis (792 males and 752 females). Patients with ulcerative colitis have slightly reduced birth rates (males at 40.8 children/1000 years, background population 43.2, females at 46.2 children/1000 years, background population 49.1). After ileal pouch-anal anastomosis, males had increased birth rates at 47.8 children/1000 years in comparison with males with ulcerative colitis without ileal pouch-anal anastomosis (40.5 children/1000 years), whereas females had reduced birth rates at 27.6 children/1000 years in comparison with females with ulcerative colitis without ileal pouch-anal anastomosis (46.8 children/1000 years). Only birth rates were investigated and not fecundability. Furthermore, there is a question about misattributed paternity, but this has previously been shown to be less than 5%. Ulcerative colitis per se has little impact on birth rates in both sexes, but ileal pouch-anal anastomosis surgery leads to a reduction in birth rates in females and an increase in birth rates in males. This has clinical impact when counseling patients before ileal pouch-anal anastomosis surgery.