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

Fertil Steril. 2019 Oct;112(4):670-676. doi: 10.1016/j.fertnstert.2019.05.039.


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.

Keywords: Embryonic aneuploidy; exogenous gonadotropins; follicular stimulation; natural cycle IVF.

Publication types

  • Observational Study

MeSH terms

  • Adult
  • Aneuploidy*
  • Embryo Implantation
  • Female
  • Fertilization in Vitro*
  • Gonadotropins / pharmacology*
  • Humans
  • Middle Aged
  • Prospective Studies


  • Gonadotropins

Associated data

  • ClinicalTrials.gov/NCT01866618