Comparison of GnRH (gonadotropin-releasing hormone) antagonist versus long GnRH agonist protocol in poor responders undergoing IVF (in vitro fertilization)

Abstract

OBJECTIVE: To compare the efficacy of GnRH antagonist protocol versus GnRH agonist protocol in poor responders undergoing IVF. DESIGN: Prospective study. MATERIALS AND METHODS: 70 poor responders were randomized into two groups:one group received 0.25mg of Cetrorelix Acetate(Cetrotide),sc(sub cutaneous)daily starting when the largest follicle had reached a diameter of 14mm; the other group received a daily dose of 0.5mg Buserlin Acetate(Superfact),sc starting at the mid-luteal phase of the preceding cycle.On the third day of the cycle,in both groups,ovarian stimulation was commenced with a fixed daily dose of hMG(Human Menopausal Gonadotropin) (300 IU daily). RESULTS: There were no significant differences between two groups in the cycle cancellation rate,duration of stimulation, consumption of gonadotropin ampules and number of retrieval oocytes,metaphase II oocytes and transferred embryos.Chemical and clinical pregnancy rates were the same in two groups.Ongoing pregnancy rate appeared higher and abortion rate was lower in antagonist group.Although, differences were not statistically significant.Table 1Stimulation and cycle outcomesAntagonist (n=35)Agonist (n=35)P-valueDuration of Stimulation (days)10.11±1.8510.06±2.900.922Total Gonadotrophin Consumption(ampules)42.57±17.6240.06±14.200.513Retrieval oocytes4.06±2.315.31±3.800.100Metaphase II oocytes3.26±2.314.17±3.120.169Embryos2.69±1.553.03±2.190.472Values are expressed as mean±SD or number(percentage),and analysed by t-test , x2 or Fisher's exact test where appropriate. Open table in a new tab Table 2Pregnancy outcomesAntagonistAgonistP-valueChemical pregnancy(βHCG)28.1%28.1%1.000clinical pregnancy(gestational sac)28.1%28.1%1.000Ongoing pregnancy(>12weeks)100%77.8%0.471Abortion11.1%33.3%0.576Values are expressed as mean±SD or number(percentage),and analysed by t-test , x2 or Fisher's exact test where appropriate. Open table in a new tab Values are expressed as mean±SD or number(percentage),and analysed by t-test , x2 or Fisher's exact test where appropriate. Values are expressed as mean±SD or number(percentage),and analysed by t-test , x2 or Fisher's exact test where appropriate. CONCLUSIONS: A flexible multi-dose GnRH antagonist protocol is feasible for patients who are poor responders on a long agonist protocol;however, our study failed to demonstrate an overall improvement in ovarian responsiveness.Clinical outcomes may be improved by developing more flexible antagonist regimens,an approach that requires further evaluation.