PROBABILITY OF PREGNANCY WITH MONO VS MULTIPLE FOLLICULOGENESIS IN WOMEN WITH UNEXPLAINED INFERTILITY
This study was conducted as a secondary analysis of a randomized controlled trial that included 12 clinical sites across the US. The trial ‘Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation with 3 treatment arms: gonadotropins, clomiphene, or letrozole, combine with intrauterine insemination (AMIGOS trial)’ included women aged 18 to 40 years old with a normal uterine cavity, at least 1 patent fallopian tube, and male partners with ≥5 million total motile sperm. A total of 900 couples were enrolled. In the overall cohort, women with one mature follicle ≥16 mm at the time of hCG trigger were less likely to have a clinical pregnancy (RR, 0.70; 95% CI, 0.54-0.89) and live birth (RR, 0.67; 95% CI, 0.54-0.89) compared to women with ≥2 follicles larger than 16 mm. Comparable outcomes were observed when follicle size cutoff was ≥18 mm; women with one follicle were less likely to have a clinical pregnancy (RR, 0.77; 95% CI, 0.60-0.98) and live birth (RR, 0.75; 95% CI 0.58-0.97). When stratified by treatment modality, women using letrozole saw no difference in chance of live birth and follicle number, while women using clomiphene or gonadotropins were more likely to have a clinical pregnancy and live birth when having ≥2 follicles as opposed to one follicle.