ORAL CONTRACEPTIVE (OcP) PRETREATMENT ACHIEVES BETTER PREGNANCY RATES IN IN VITRO FERTILIZATION (IVF) ANTAGONISTS GnRH FLEXIBLE PROTOCOLS: A PROSPECTIVE RANDOMIZED STUDY

OBJECTIVE: To compare IVF performance in antagonist GnRh cycles with and without oral contraceptive pre-treatment. DESIGN: Prospective, randomized, controlled study. MATERIALS AND METHODS: 210 patients with IVF indication were randomized whether to receive or not pre-treatment with OCP. Inclusion criteria: Age ≤39, first IVF attempt, basal FSH ≤ 12 mIU/ml. Patients with PCO (polycystic ovarian syndrome) criteria, prior ovarian surgery and TESE needing were excluded. Group A recived 0.02 mg etinilestradiol - 0.1 mg levonorgestrel for 14/25 days in the preceding cycle for synchronization. Patients were stimulated with recFSH 200 IU/day from menstrual cycle day 2 to 3, HMG 225 UI/day from day 4 and GnRh antagonist (Cetrorelix 0.25 mg) in a flexible protocol starting with 14 mm leading follicle continuing both daily until the day of hCG. Oo- cyte maturation was triggered by rechCG 250 μg. Embryo transfer was performed 3 days later. Group B did the same protocol except the pre-treatment. Primary endpoint: Clinical pregnancy rate. Statistical analysis: chi2 tests, t test. RESULTS: 105 patients were assigned to each group. 4 patients in group A and patient in group B were cancelled. There was no difference in total gonadotrophin (2411,61+/-774,13 vs 2251,43+/-524,82UI), stimulation days (10,35+/-1,94 vs. 10,57+/-1,47) fertilization rate (72,16 vs 77,77%), implantation rate (23,13 vs. 19,98%) between both groups. Total number of oocytes retrieved, (8,93+/-5,41 vs 11,85+/-8,23) total number of embryos achieved (4,71+/-2,89 vs 6,17+/-3,93), and good embryo quality rate (52,12 vs 67,21%) were higher in group B. Clinical pregnancy rate was significantly higher in group A. CONCLUSION: Contraceptive pre-treatment facilitates cycle scheduling for IVF. Although patients not pre-treated achieved more oocytes, the proportion of MII oocytes and embryos, stayed constant in both groups. As shown, OCP pre-treatment, significantly increased pregnancy rate.