Objectives:The appropriate and recommended delivery mode after ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC) has not been sufficiently evaluated. This study was designed to compare the delivery outcomes associated with cesarean section (CS) and vaginal delivery (VD) after IPAA. Methods: We conducted a questionnaire-based survey of female patients who underwent IPAA for UC between July 1987 and May 2018. Additionally, we reviewed clinical data and collected information regarding pouch function and postpartum complications. Results: In total, 45 patients had 68 deliveries, including 64 CS deliveries and four VDs. Fecal incontinence worsened in seven patients, including six CS patients and one VD patient. The Wexner scores of these patients before and after delivery were 5.4 ± 0.4 and 14.8 ± 1.0, respectively (p = 0.005). Four patients in the CS group and one in the VD group (p = 0.32) had increased stool frequency. Bowel obstructions developed during 11/64 (17.2%) deliveries, and one patient required surgical intervention. One patient with four VDs (three before IPAA and one after IPAA) developed vaginal fistula 5 months after the final VD. Information on episiotomies could not be obtained. Conclusions: Pouch function can decline even after CS. Notably, bowel obstruction can develop after CS. However, we cannot recommend a particular delivery method after IPAA. Further analyses to elucidate the relationship between CS and postoperative complications or vaginal fistula and episiotomy in VDs should be conducted.