Embryonic aneuploidy rates are equivalent in natural cycles and gonadotropin-stimulated cycles.

OBJECTIVE: To determine if natural selection and follicular stimulation produces a lower risk for embryonic aneuploidy than that attained following superovulation with exogenous gonadotropins. DESIGN: Prospective observational with historical control group. SETTING: Large academically affiliated private practice. PATIENT(S): All patients presenting for their evaluation for infertility were offered participation in the study. INTERVENTION(S): All participants in the natural cycle group underwent an unstimulated in vitro fertilization (IVF) cycle. A subsequent frozen embryo transfer was performed if a euploid blastocyst was attained. MAIN OUTCOME MEASURE(S): Rates of embryonic aneuploidy attained in unstimulated IVF cycles were compared to those observed in age-controlled historical cohort undergoing conventional stimulated IVF cycles with exogenous gonadotropins. RESULT(S): Aneuploidy rates were equivalent in unstimulated and stimulated IVF cycles. The prevalence of aneuploidy in natural cycles increased with the age of the female partner in a manner identical to that seen in stimulated IVF cycles. Finally, sustained implantation rates of euploid blastocysts were equivalent in natural and stimulated IVF cycles. CONCLUSION(S): Rates of embryonic aneuploidy are not impacted by follicular stimulation with exogenous gonadotropins. Prior concerns of inducing a higher risk of embryonic aneuploidy are not supported by this data. CLINICAL TRIAL REGISTRATION NUMBER: NCT01866618.