OBJECTIVE: To compare the early-cleavage rates and the implantation potential of embryos between the GnRH antagonist and agonist long stimulation protocols in women older than 35 years. DESIGN: Retrospective analysis. SETTING: Academic medical center. PATIENTS: Two hundred twenty patients older than 35 years old underwent IVF. INTERVENTION(S): Sixty-eight patients received GnRH antagonist protocol (GnRH antagonist group) and 152 patients received GnRH agonist long stimulation protocol (GnRH agonist group). MAIN OUTCOME MEASURE(S): Early-cleavage rate of zygotes, implantation rate, and pregnancy rate. RESULT(S): Early-cleavage rate of zygotes was significantly lower in the GnRH antagonist group than agonist group (21.8% vs. 32.6%, P<.0001). In the GnRH antagonist group, the pregnancy rate was not significantly different between the early-cleavage and late-cleavage subgroups (40.0% vs. 47.4%). In the GnRH agonist group, the pregnancy rate was significantly higher in the early-cleavage subgroup than in the late-cleavage subgroup (61.0% vs. 29.8%, P<.0001). CONCLUSION(S): In women older than 35 years, the early-cleavage rate of zygotes is significantly lower in the GnRH antagonist group than the agonist group. Early-cleavage status of zygotes is not a reliable predictor for embryo implantation in patients receiving the GnRH antagonist protocol.
OBJECTIVE: To compare the early-cleavage rates and the implantation potential of embryos between the GnRH antagonist and agonist long stimulation protocols in women older than 35 years. DESIGN: Retrospective analysis. SETTING: Academic medical center. PATIENTS: Two hundred twenty patients older than 35 years old underwent IVF. INTERVENTION(S): Sixty-eight patients received GnRH antagonist protocol (GnRH antagonist group) and 152 patients received GnRH agonist long stimulation protocol (GnRH agonist group). MAIN OUTCOME MEASURE(S): Early-cleavage rate of zygotes, implantation rate, and pregnancy rate. RESULT(S): Early-cleavage rate of zygotes was significantly lower in the GnRH antagonist group than agonist group (21.8% vs. 32.6%, P<.0001). In the GnRH antagonist group, the pregnancy rate was not significantly different between the early-cleavage and late-cleavage subgroups (40.0% vs. 47.4%). In the GnRH agonist group, the pregnancy rate was significantly higher in the early-cleavage subgroup than in the late-cleavage subgroup (61.0% vs. 29.8%, P<.0001). CONCLUSION(S): In women older than 35 years, the early-cleavage rate of zygotes is significantly lower in the GnRH antagonist group than the agonist group. Early-cleavage status of zygotes is not a reliable predictor for embryo implantation in patients receiving the GnRH antagonist protocol.