When to stop? assessing the appropriate cycle of ovulation induction with timed intercourse in letrozole- or clomiphene citrate-sensitive polycystic ovary syndrome

To study how many cycles of ovulation induction with timed intercourse were appropriate for PCOS patients sensitive to letrozole or clomiphene citrate. A prospective study. A total of 655 women with PCOS were included who underwent 2633 cycles with ovulation induction followed by timed intercourse between August 1, 2020 and June 30, 2023. Sensitivity to letrozole or clomiphene citrate was confirmed via hospital monitoring during the first cycle. Subsequent cycles were managed using home ovulation monitoring. Cumulative live birth rate of the study cohort was defined as the number of women who achieved at least one live birth divided by the total study population. A total of 306 patients achieved 372 pregnancies, 257 clinical pregnancies and 206 live births. The cumulative pregnancy, clinical pregnancy and livebirth were 46.72%, 39.24%, and 31.45%, respectively. The cumulative live birth rate plateaued after eight cycles of ovulation induction with timed intercourse. Weight reduction was associated with an increase in the maximal cumulative live birth rate from 28.00% to 39.02%. Additionally, metformin use was associated with reaching the cumulative live birth plateau earlier. It is practical to suggest that eight cycles of ovulation induction with timed intercourse would reach the maximal cumulative live birth rate for PCOS patients sensitive to letrozole or clomiphene citrate. Weight loss and metformin use may further improve outcomes to live birth.