Comparison between two forms of vaginally administered progesterone for luteal phase support in assisted reproduction cycles

The use of progesterone for luteal phase support has been demonstrated to be beneficial in assisted reproduction cycles using gonadotrophin-releasing hormone analogues (GnRHa). Two micronized progesterone preparations are available for vaginal administration: capsules and gel. The objective of this study was to compare the efficacy of these two forms for luteal phase support in assisted reproduction cycles. A total of 244 couples undergoing IVF/intracytoplasmic sperm injection cycles were included in the study and were randomly allocated (sealed envelopes) into two groups: group 1 (122) received vaginal capsules of 200 mg of micronized progesterone (Utrogestan), 3 times daily, and group 2 (122) received micronized progesterone in gel (Crinone 8%), once daily. Both groups received progesterone for 13 days beginning day 1 after oocyte retrieval, continuing until the pregnancy test was performed and until 12 weeks of pregnancy. Groups were compared by clinical data and assisted reproduction results and had similar ages and causes of infertility. Although the pregnancy rate was higher for those receiving progesterone gel than capsules (44.26 and 36.06% respectively), this difference was not statistically significant. The study showed that vaginal progesterone gel and capsules used for luteal phase support in assisted reproduction cycles with long protocol GnRHa result in similar pregnancy rates.