Background and Aims Inflammatory bowel disease (IBD) has been associated with reduced female fertility. We analyze fertility in a national cohort of women with IBD. Methods Assessment of fertility in women with IBD aged 15–44 years in 1964–2014, identified from the Swedish National Patient Register and a matched cohort (ratio 1:5). Patients with indeterminate colitis or inconsistent IBD coding was classified as IBD-unclassified (IBD-U). Results The cohorts included 27,331 women with IBD and 131,892 matched individuals. The fertility rate in IBD was 1.52 (SD 1.22) births per 1,000 person-years and 1.62 (SD 1.28) (p <0.001) in matched individuals. Fertility was impaired in all IBD subtypes compared with the matched cohort (hazard ratio Crohn’s disease (CD) 0.88, 95% CI 0.85–0.91, IBD-U 0.86, 95% CI 0.83–0.89 and ulcerative colitis (UC) 0.96, 95% CI 0.93–0.98). Fertility improved during the study period for the IBD cohort except for CD. Parity Progression Ratio, the proportion of IBD women progressing from one parity to the next compared with the matched cohort, was decreased at all parity levels for CD and IBD-U but only for multiparous women in UC. Contraceptive usage was higher in IBD, both before and after the diagnosis. Disease severity, bowel resections and perianal disease in CD affected fertility negatively. Conclusions Fertility was impaired mainly in women with CD and IBD-U, and less so in UC. During the study period fertility improved in women with UC or IBD-U. Some results suggest a role of voluntarily reduced fertility.

BackgroundThe time of ovulation has since long been believed to be concealed to male heterosexual partners. Recent studies have, however, called for revision of this notion. For example, male testosterone concentrations have been shown to increase in response to olfactory ovulation cues, which could be biologically relevant by increasing sexual drive and aggressiveness. However, this phenomenon has not previously been investigated in real-life human settings. We therefore thought it of interest to test the hypothesis that males' salivary testosterone concentrations are influenced by phases of their female partners' menstrual cycle; expecting a testosterone peak at ovulation.MethodsThirty young, healthy, heterosexual couples were recruited. During the course of 30-40 days, the women registered menses and ovulation, while the men registered sexual activity, physical exercise, alcohol intake and illness (confounders), and obtained daily saliva samples for testosterone measurements. All data, including the registered confounders, were subjected to multiple regression analysis.ResultsIn contrast to the hypothesis, the ovulation did not affect the testosterone levels, and the resulting testosterone profile during the menstrual cycle was on the average flat. The specific main hypothesis, that male testosterone levels on the day of ovulation would be higher than day 4 of the cycle, was clearly contradicted by a type II error(β)-analysis (< 14.3% difference in normalized testosterone concentration; β = 0.05).ConclusionsEven though an ovulation-related salivary testosterone peak was observed in individual cases, no significant effect was found on a group level.

Background: Onset of inflammatory bowel disease (IBD) in men is most common during reproductive age, but little is known about the impact on fertility. Previous studies of fertility in men were small. Aim: To assess fertility among young men with IBD Methods: Fertility was assessed in a national cohort of men with IBD aged 15-44 years in 1964-2014, identified from the Swedish National Patient Register, and in a reference cohort matched for age and place of residence (ratio 1:5). Information about childbirths was found in the Swedish Multi-Generation Register. Patients with indeterminate colitis or inconsistent IBD coding were classified as IBD-unclassified (IBD-U). Results: The cohorts included 29,104 men with IBD and 140,901 matched individuals. IBD patients had a lower fertility rate (number of births per 1000 person years) compared with the matched individuals; 1.28 (SD 1.27) versus 1.35 (SD 1.31;p < 0.001). Fertility was somewhat impaired in all IBD subtypes compared with the matched cohort; ulcerative colitis (UC) (hazard ratio [HR] 0.93, 95% CI 0.91-0.96), Crohn's disease (CD) (HR 0.95, 95% CI 0.92-0.98) and IBD-U 0.92, 95% CI 0.89-0.95.The cumulated total parity and the parity progression were also decreased for all IBD subtypes. Within the IBD cohort disease severity, intensity of medical treatment (CD) and bowel surgery (IBD-U) were further associated with impaired fertility.Conclusions: This nationwide cohort study shows only slightly impaired fertility in men with IBD.