Resource-conscious care: time to pregnancy and IUI cycle outcomes in female same-sex couples.

RESEARCH QUESTION: Does the clinical pregnancy rate (CPR) for the first cycle, time to pregnancy, and cumulative CPR up to six consecutive cycles differ between female same-sex couples undergoing intrauterine insemination (IUI) alone and those undergoing IUI with ovarian stimulation? DESIGN: This retrospective cohort study evaluated 554 female same-sex couples undergoing IUI alone (n = 264) or IUI with ovarian stimulation (n = 290) at a single centre using cryopreserved donor spermatozoa from January 2012 to January 2022. RESULTS: Overall, CPR for the first cycle was 17.9% (99/554). In adjusted analyses, there was no significant difference in CPR in IUI with ovarian stimulation versus IUI alone [adjusted OR (aOR) 0.90, 95% CI 0.53-1.54], nor when stratified by maternal age group (<35 years, aOR 0.94, 95% CI 0.50-1.75; 35-37 years, aOR 0.82, 95% CI 0.21-3.33; ≥38 years, aOR 1.50, 95% CI 0.16-14.28). The median time to conception resulting in an ongoing pregnancy was five cycles (overall cohort) and four cycles (age <35 years). However, individuals aged ≥35 years had a cumulative CPR after six cycles <50% (log rank test P = 0.0071). The respective cumulative CPR after three and six cycles were: age <35 years: 40.8% and 60.7%; age 35-37 years: 35% and 48.9%; and age >38 years: 24.9% and 33.6%, respectively. CONCLUSION: For female same-sex couples, IUI alone had a similar success rate to IUI with ovarian stimulation. In women aged <35 years, >50% are likely to achieve pregnancy after six IUI cycles, but in those aged ≥35 years, alternative fertility treatment should be expedited.