Ovulation induction with letrozole and dexamethasone in infertile patients with letrozole-resistant polycystic ovary syndrome

To assess efficacy of adjuvant dexamethasone during letrozole cycles for ovulation induction (OI) in women with letrozole-resistant polycystic ovary syndrome (PCOS).

We retrospectively evaluated 42 cycles of OI from 28 infertile women with letrozole-resistant PCOS between September 2019 and November 2022. Letrozole was initiated on cycle day 3 for 5 days and increased via a stair-step approach to 7.5 mg as indicated. Patients were deemed letrozole-resistant if no dominant follicle was identified on transvaginal ultrasound following this dose. Resistant patients then received 5 additional days of letrozole 7.5 mg with low-dose dexamethasone 0.5 mg for 7 days and had a repeat ultrasound. The primary outcome was ovulation rate determined by the presence of a dominant follicle on ultrasound. Secondary outcomes included endometrial thickness, number of measurable follicles, and pregnancy outcomes among responders.

Twenty-two of 28 (79%) letrozole-resistant PCOS patients had evidence of ovulation after the addition of dexamethasone in 35 out of 42 (83%) cycles. Clinical pregnancy occurred in 20% of ovulatory cycles with a cumulative rate of 32%. All clinical pregnancies resulted in a live birth. Patients who responded to adjuvant dexamethasone were more likely to have a shorter duration of infertility; however, there were no differences in other demographics, serum androgens including DHEA-S, or pretreatment glycemic status.

Adding dexamethasone to letrozole increased ovulation rates in letrozole-resistant PCOS patients undergoing OI with similar pregnancy outcomes to prior studies. The addition of dexamethasone is an effective, inexpensive, and safe option for PCOS patients otherwise at risk for cycle cancelation.