A comparison of the effects of three different estrogen used for endometrium preparation on the outcome of day 5 frozen embryo transfer cycle

OBJECTIVE: To evaluate the effects of three different estrogen used for endometrium preparation on pregnancy rate, as well as hormone profile on day 5 frozen embryo transfer (FET) cycles. METHODS: Retrospective, observational study. Setting: A tertiary teaching and research private reproductive medicine center. Patients: Ninety patients who were undergoing endometrium preparation for day five frozen embryo transfer cycle (FET). Intervention(s): The women were divided in three groups according to the administration route of estrogen (E2): oral (Primogyna), transdermal patches (Estradot), or transdermal gel (Oestrogel Pump). These administration routines of estrogen are equivalent to 6mg of estradiol daily. All women received 600mg of vaginal progesterone (P) per day (Utrogestan) for luteal phase support. We drew blood samples on starting P day, as well as on beta hCG day for E2 and P measurements. Main Outcome Measure(s): Clinical pregnancy rates (PR). RESULTS: Patient features in the three groups were comparable. There were no significant differences concerning implantation rate, clinical PR, miscarriage rate, multiple-pregnancy rate, or E2 and P levels on starting P day and on beta hCG day. CONCLUSIONS: In FET cycles with oral (Primogyna) or transdermal patches (Estradot), or transdermal gel (Oestrogel Pump), there was no significant difference on pregnancy rates.