BACKGROUND: Single-embryo transfer has been recommended to reduce the incidence of multiple gestations when in vitro fertilization is performed in women under 36 years of age. We designed a prospective, randomized, co...BACKGROUND: Single-embryo transfer has been recommended to reduce the incidence of multiple gestations when in vitro fertilization is performed in women under 36 years of age. We designed a prospective, randomized, controlled trial to determine whether there were any differences in the rates of pregnancy and delivery between women undergoing transfer of a single cleavage-stage (day 3) embryo and those undergoing transfer of a single blastocyst-stage (day 5) embryo. METHODS: We studied 351 infertile women under 36 years of age who were randomly assigned to undergo transfer of either a single cleavage-stage embryo (176 patients) or a single blastocyst-stage embryo (175 patients). Multifollicular ovarian stimulation was performed with a gonadotropin-releasing hormone antagonist and recombinant follicle-stimulating hormone. RESULTS: The study was terminated early after a prespecified interim analysis (which included 50 percent of the planned number of patients) found a higher rate of pregnancy among women undergoing transfer of a single blastocyst-stage embryo (P = 0.02). The rate of delivery was also significantly higher in this group than in the group undergoing transfer of a single cleavage stage embryo (32.0 percent vs. 21.6 percent; relative risk, 1.48; 95 percent confidence interval, 1.04 to 2.11). Two multiple births occurred, both of monozygotic twins, both of which were in the group undergoing transfer of a single cleavage-stage embryo. CONCLUSIONS: These findings support the transfer of a single blastocyst-stage (day 5) embryo in infertile women under 36 years of age.展开更多
Objective To assess the effect of altering the timing of hCG administ ration on ongoing pregnancy rates in patients stimu-lated with recombinant FSH (rec-FSH ) and GnRH antagonists for IVF. Design Prospective, randomi...Objective To assess the effect of altering the timing of hCG administ ration on ongoing pregnancy rates in patients stimu-lated with recombinant FSH (rec-FSH ) and GnRH antagonists for IVF. Design Prospective, randomized, controlled trial . Setting Tertiary referral center. Patient(s) Four hundred thirteen patients un dergoing IVF. Intervention(s) Rec-FSH stimulation starting on day 2 of the cycl e combinedwith daily GnRH antagonist starting on day 6 of stimulation. Patients were randomized to receive 10,000 IU of hCG either as soon as at least three fol licles were ≥17 mm on ultrasound (early-hCG group, 208 patients) or 2 days lat er after this criterion was met (late-hCG group, 205 patients). Main outcome me asure(s) Ongoing pregnancy rate. Result(s) Fertilization rates and number and qu ality of embryos transferred did not differ between the two groups. However, a s ignificantly lower ongoing pregnancy rate was present in the late-hCG as compar ed with the early-hCG group (25.0%vs. 35.6%, respectively). Conclusion(s) Pro longation of the follicular phase in patients stimulated with rec-FSH and GnRH antagonists for IVF does not affect oocyte or embryo quality but is associated w ith a significantly lower ongoing pregnancy rate.展开更多
文摘BACKGROUND: Single-embryo transfer has been recommended to reduce the incidence of multiple gestations when in vitro fertilization is performed in women under 36 years of age. We designed a prospective, randomized, controlled trial to determine whether there were any differences in the rates of pregnancy and delivery between women undergoing transfer of a single cleavage-stage (day 3) embryo and those undergoing transfer of a single blastocyst-stage (day 5) embryo. METHODS: We studied 351 infertile women under 36 years of age who were randomly assigned to undergo transfer of either a single cleavage-stage embryo (176 patients) or a single blastocyst-stage embryo (175 patients). Multifollicular ovarian stimulation was performed with a gonadotropin-releasing hormone antagonist and recombinant follicle-stimulating hormone. RESULTS: The study was terminated early after a prespecified interim analysis (which included 50 percent of the planned number of patients) found a higher rate of pregnancy among women undergoing transfer of a single blastocyst-stage embryo (P = 0.02). The rate of delivery was also significantly higher in this group than in the group undergoing transfer of a single cleavage stage embryo (32.0 percent vs. 21.6 percent; relative risk, 1.48; 95 percent confidence interval, 1.04 to 2.11). Two multiple births occurred, both of monozygotic twins, both of which were in the group undergoing transfer of a single cleavage-stage embryo. CONCLUSIONS: These findings support the transfer of a single blastocyst-stage (day 5) embryo in infertile women under 36 years of age.
文摘Objective To assess the effect of altering the timing of hCG administ ration on ongoing pregnancy rates in patients stimu-lated with recombinant FSH (rec-FSH ) and GnRH antagonists for IVF. Design Prospective, randomized, controlled trial . Setting Tertiary referral center. Patient(s) Four hundred thirteen patients un dergoing IVF. Intervention(s) Rec-FSH stimulation starting on day 2 of the cycl e combinedwith daily GnRH antagonist starting on day 6 of stimulation. Patients were randomized to receive 10,000 IU of hCG either as soon as at least three fol licles were ≥17 mm on ultrasound (early-hCG group, 208 patients) or 2 days lat er after this criterion was met (late-hCG group, 205 patients). Main outcome me asure(s) Ongoing pregnancy rate. Result(s) Fertilization rates and number and qu ality of embryos transferred did not differ between the two groups. However, a s ignificantly lower ongoing pregnancy rate was present in the late-hCG as compar ed with the early-hCG group (25.0%vs. 35.6%, respectively). Conclusion(s) Pro longation of the follicular phase in patients stimulated with rec-FSH and GnRH antagonists for IVF does not affect oocyte or embryo quality but is associated w ith a significantly lower ongoing pregnancy rate.
