Intramuscular versus vaginal progesterone in assisted reproduction

Abstract

Objective: A luteal phase defect has been demonstrated in IVF cycles using a gonadotrophin releasing hormone agonist (GnRH-a). Progesterone appears to be necessary for implantation and maintenance of an early intrauterine pregnancy. To determine the effectiveness of two routes of progesterone supplementation by intramuscolar vs. vaginal administration, for luteal phase support of patients undergoing in vitro fertilization (IVF) procedure. Materials and Methods: 224 patients were randomly allocated to two groups in order to compare two treatment protocols: group A natural progesterone 50 mg/day i.m. (Prontogest, AMSA, Italy,); group B: micronized progesterone 200 mg/day vaginal (Esolut, Angelini, Italy). Pregnancy rate per embryo transfer and endometrial thickness in mid luteal phase were compared. Results: There were no statistically significant differences in pregnancy rate between the two groups. The pregnancy rate per transfer for i.m. progesterone groups was 24.1% and for vaginal group was 26.7%. The endometrial thickness was not statistically differences between the two group. (Group A: 12mm; Group B: 11 mm. ). Conclusion: The route of post-transfer progesterone administration does not appear to affect the pregnancy rate in IVF cycles. Comparable results can be achieved with both intramuscolar and vaginal therapy. However the last route may be preferable due to better patients compliance and lower side effects.