Hong KH, Franasiak JM, Werner MM, et al. - Researchers examined risk for embryonic aneuploidy in correlation with natural selection and follicular stimulation vs that attained following superovulation with exogenous gonadotropins. All patients presenting for their evaluation for infertility at a large academically affiliated private practice were offered participation in the study. An unstimulated in vitro fertilization (IVF) cycle was performed in all participants in the natural cycle group. Subsequently, frozen embryo transfer was offered if a euploid blastocyst was attained. Comparison of rates of embryonic aneuploidy attained in unstimulated IVF cycles vs those observed in age-controlled historical cohort undergoing conventional stimulated IVF cycles with exogenous gonadotropins was performed. Outcomes revealed no impact of follicular stimulation with exogenous gonadotropins on the rates of embryonic aneuploidy. The data thereby do not support the prior concerns of inducing a higher risk of embryonic aneuploidy.