Luteal support for IVF/ICSI cycles with Crinone 8% (90 mg) twice daily results in higher pregnancy rates than with intramuscular progesterone.

Background: The use of progesterone for luteal support has been demonstrated to be beneficial in assisted reproductive cycles, yet the optimal route of progesterone administration has still not been established. This article is a retrospective study in a tertiary reproductive medical unit to compare luteal progesterone supplementation with vaginal gel or intramuscular progesterone.

Methods: A total of 144 in vitro fertilization or intracytoplasmic sperm injection cycles were analyzed, 67 cycles using vaginal gel 90 mg twice daily and 77 cycles using intramuscular progesterone 50 mg daily as luteal support.

Results: Both groups had similar mean age, cause of infertility, baseline hormone levels, dosage of recombinant follicle-stimulating hormone, number of retrieved and fertilized oocytes, and number of transferred embryos. The vaginal gel group had significantly lower mid-luteal serum progesterone levels but higher implantation rate (32.5% vs. 18.5%, p = 0.001) and ongoing pregnancy rate (55.2% vs. 32.5%, p = 0.006). Within each group, mid-luteal serum progesterone levels between pregnant or non-pregnant patients were comparable. For patients with serum estradiol levels on day of human chorionic gonadotropin greater than 5,000 pg/mL, vaginal gel still resulted in better ongoing pregnancy and implantation rates.

Conclusion: The use of vaginal progesterone gel twice daily for luteal support results in better pregnancy outcomes than intramuscular progesterone. A high local progesterone effect from vaginal gel might improve endometrial receptivity under extraordinarily high serum estradiol levels.