Different progestin-primed ovarian stimulation protocols in infertile women undergoing in vitro fertilization/intracytoplasmic sperm injection: an analysis of 1188 cycles.

Purpose: To evaluate the efficacy in suppressing the premature LH surge, embryo quality and pregnancy outcomes of progestin-primed ovarian stimulation (PPOS) protocols using medroxyprogesterone acetate versus utrogestan in women of all ages undergoing in vitro fertilization or intracytoplasmic sperm injection.

Methods: 1188 patients were enrolled in the retrospective study, of which 1002 patients were treated with medroxyprogesterone acetate (M group) and recombinant follicle-stimulating hormone (r-FSH)simultaneously from day 3 of the cycle until trigger day, while 186 patients were treated with utrogestan (U group) and r-FSH instead. Viable embryos were cryopreserved for later transfer in both groups. Differences in baseline characteristics, ovarian stimulation characteristics, endocrinological characteristics, embryo development and clinical outcome between two groups were assessed. Statistical analyses were performed stratified by age and number of oocytes retrieved.

Results: No significant differences were observed in the baseline characteristics, ovarian stimulation characteristics and clinical outcome of patients between groups. However, blastulation rate in the U group was significantly higher than that in the M group (49.4% vs. 32.9%, P < 0.001). During ovarian stimulation, LH levels remained steady in both groups. Higher percentage of premature LH surge was found in the U group (2.4% vs. 10.2%, P < 0.001), especially for patients aged more than 35 years or who had three oocytes or less retrieved.

Conclusions: Both the administration of medroxyprogesterone acetate and utrogestan in PPOS were sufficient to prevent an untimely LH rise, while for patients with poor ovarian response or aged above 35 years, MPA may result in a more satisfactory LH level. PPOS protocol using medroxyprogesterone acetate or utrogestan was comparable in terms of oocytes and pregnancy outcome, whereas the administration of utrogestan may result in an improved blastulation than medroxyprogesterone acetate, which needs further exploration.