Intrauterine insemination or intracervical insemination with cryopreserved donor sperm in the natural cycle: a cohort study

main results and the role of chance: Baseline characteristics were equally distributed (mean age 34.0 years for the IUI group versus 33.8 years for the ICI group), while in the IUI group, there were more lesbian women than in the ICI group (40.6% for IUI compared with 31.8% for ICI). Cumulative OPRs up to six treatment cycles were 40.5% for IUI and 37.9% for ICI. This corresponds with a hazard rate ratio of 1.02 [95% confidence interval (CI) 0.84 –1.23] after controlling for female age and indication. Increasing female age was associated with a lower OPR, in both the IUI and ICI groups with a hazard ratio for ongoing pregnancy of 0.94 per year (95% CI 0.93 –0.97). limitations,reasonsforcaution: This study is prone to selection bias due to its retrospective nature. As potential confounders such as parity and duration of subfertility were not registered, the effect of these potential confounders could not be evaluated. wider implications of the findings: In women inseminated with cryopreserved donor sperm in the natural cycle, we found no substantial benefit of IUI over ICI. A randomized controlled trial with economic analysis alongside, it is needed to allow a more definitive conclusion on the cost-effectiveness of insemination with cryopreserved donor sperm.