Gonadotropin stimulation demonstrates a ceiling effect on in vitro fertilization outcomes

ObjectiveTo determine the effect of number of oocytes retrieved and number of 2PN embryos developed on in vitro fertilization (IVF) outcomes.DesignRetrospective data analysis.SettingUniversity practice.Patient(s)Reproductive-aged women (n = 467).Intervention(s)First fresh nondonor cycle of IVF.Main Outcome Measure(s)Clinical pregnancy rateResult(s)Clinical pregnancy rates increase until age 30 (odds ratio (OR) 1.72 per year (95% confidence interval 1.19–2.49)) before demonstrating a linear decline. In subjects <37 years old, maximal clinical pregnancy rates are seen when 20 oocytes were retrieved (OR 1.03 (0.96–1.11)), five 2-pronuclei (2PN) embryos developed (OR 1.91 (1.29–2.87)), and no more than two embryos transfered (OR 0.72 (0.56–0.92) for each additional embryo transferred >2). In subjects ≥37 years old, maximum clinical pregnancy rates were achieved in subjects who had ten oocytes retrieved (OR 1.09 (1.01–1.18)), 20 2PN embryos developed (OR 1.29 (1.03–1.62)), and no more than two embryos transfered (OR 0.72 (0.56–0.92) for each additional embryo transferred >2).Conclusion(s)The odds of achieving a successful clinical pregnancy with IVF are greatest with retrieval of approximately 20 oocytes, transfer of no more than 2 embryos, and the development of about five 2PN embryos in women <37 years old and ten 2PN embryos in women ≥37 years old.