Vaginal gel versus intramuscular progesterone for luteal phase supplementation: a prospective randomized trial

The aim of this randomized study was to compare the efficacy of intramuscular progesterone (IMP) and progesterone in vaginal gel (VGP) at two different doses for luteal support in IVF. A total of 412 patients, aged between 28 and 37 years, were randomized into three groups. The day after oocyte retrieval each patient began supplementation with one of the following: IMP 50 mg daily (150 patients), VGP 90 mg once daily (143 patients), or VPG 90 mg twice daily (148 patients). No significant difference was found between the three groups in any of the endpoints. The rate of positive β-human chorionic gonadotrophin per transfer was 38.4% with IMP, 35.0% with VPG once daily and 43.1% with VPG twice daily. Clinical pregnancy rate per transfer and implantation rate were 32.6% and 19.6% with IMP, 26.3% and 16.4% with one dose of VGP, and 37.2% and 21.1% with two doses of VGP. Live birth rate per transfer was 26.1%, 23.4% and 29.9%, respectively. Progesterone vaginal gel can be successfully used as an alternative to intramuscular progesterone for luteal support in IVF. One daily dose appears sufficient to induce clinical pregnancies and live births at a rate comparable to intramuscular supplementation.