Research question: Should intrauterine insemination be carried out before or after follicle rupture, and is there a difference in sex ratio, according to follicle rupture at the time of insemination? Design: In this retrospective cohort study conducted at the Fertility Clinic, Odense University Hospital, Denmark, data from 6701 homologous insemination cycles were analysed. Follicle rupture was determined by transvaginal ultrasonography at the time of insemination. The pregnancy rate, clinical pregnancy rate (CPR) and live birth rate (LBR) were recorded. Results: In 2831 cycles (42.2%), follicle rupture had occurred at the time of insemination, whereas, in 3870 cycles (57.8%), no follicle rupture had occurred at the time of insemination. Overall, 1186 (17.7%) cycles resulted in a positive pregnancy test and no significant differences were found in pregnancy rate between rupture and no rupture of follicle (17.8% versus 17.7%, P = 0.90). Follicle rupture before or after insemination did not affect CPR (14.8% versus 15.0%, P = 0.86) or LBR (11.9% versus 12.2%, P = 0.75) per cycle. Moreover, the sex ratio of children born did not depend on follicle rupture (P = 0.20). After logistic regression with cluster and adjusting for baseline characteristics, no significant differences between groups were observed. Conclusion: Ovulation at the time of insemination is not associated with pregnancy rate, CPR, LBR or gender.