BACKGROUND: Women with inflammatory bowel disease (IBD) may choose to remain childless due to a lack of IBD-specific reproductive knowledge.OBJECTIVES: To examine the effects of IBD-specific reproductive knowledge and discussion of family planning with a physician on childlessness among women with IBD.METHODS: Female IBD patients 18 to 45 years of age completed the Crohn’s and Colitis Pregnancy Knowledge questionnaire (CCPKnow), and answered questions regarding reproductive history, plans to have children and discussion of family planning with a physician. CCPKnow scores were grouped according to poor (0 to 7), adequate (8 to 10), good (11 to 13) and very good (14 to 17).RESULTS: Of 434 eligible women, 248 (57.1%) completed the questionnaires. Of these 248 women, 51.6% were childless and, among these, 12.9% were voluntarily childless and 12.1% were trying to become pregnant. Childless women had a lower median CCPKnow score than women with children (6.0 versus 8.0; P=0.001). After adjusting for current age and marital status, each one point increase in the CCPKnow score corresponded to 8% lower odds of childlessness (OR 0.92 [95% CI 0.86 to 0.99]), 9% lower odds of voluntary child-lessness (OR 0.91 [95% CI 0.79 to 1.0]) and 20% higher odds of trying to become pregnant (OR 1.2 [95% CI 1.0 to 1.4]). Discussion of family planning with a gastroenterologist corresponded to 72% lower odds of a poor CCPKnow score (OR 0.28 [95% CI 0.15 to 0.53]) and of voluntary childlessness (OR 0.28 [95% CI 0.057 to 1.3]).CONCLUSION: In the present study, higher IBD-specific reproductive knowledge lowered the odds of childlessness among women with IBD. Discussion of family planning with a physician was associated with higher CCPKnow scores and lower odds of voluntary childlessness.