LUTEAL PHASE SUPPORT WITH PROGESTERONE DOES NOT IMPROVE PREGNANCY RATES IN PATIENTS UNDERGOING OVARIAN STIMULATION WITH LETROZOLE
Supplemental progesterone is routinely used as luteal phase support in non-IVF fertility treatments, despite limited data to support its use. This was a retrospective cohort study that included 273 patients undergoing ovarian stimulation with letrozole paired with IUI or timed intercourse between January 2018 and October 2021. A total of 492 letrozole ovarian cycles were included. Ovulation stimulation protocol included baseline transvaginal ultrasound on cycle day 2 or 3, and letrozole (2.5, 5, or 7.5 mg) daily for five days. When given, vaginal progesterone (Prometrium, 200 mg) was initiated two days post-IUI or 4 days post-hCG trigger in timed intercourse cycles, twice or three times daily. Of these cycles, there was not a significant difference in multifollicular development between those who did and those who did not receive progesterone (P=0.337), as well as no difference in unadjusted clinical pregnancy rate between those who did and those who did not receive progesterone (P=0.645). Live birth rate and infant weight at delivery were similarly not significantly different between groups (P=0.599, 0.076, respectively).