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Embryos with a Mosaic Result: the Known and Unknown Reproductive Potential

  • Reproductive Endocrinology and Infertility (REI) (R Anchan, Section Editor)
  • Published:
Current Obstetrics and Gynecology Reports Aims and scope Submit manuscript

Abstract

Purpose of Review

Interest regarding the transfer of embryos with a mosaic result has increased in recent years as outcome data continues to aggregate since the first published report of livebirths after the transfer of embryos with a mosaic result in 2015. The purpose of this review is to distill the available published literature on the transfer of embryos with a mosaic result in order to empower clinicians to understand and counsel patients on this topic.

Recent Findings

Embryos with a mosaic result have clear reproductive potential, though the live birth rate from these embryos is usually reported to be lower than euploid embryos. The transfer of these embryos is now common enough that researchers are developing ranking systems that prioritize different mosaic results based on their likelihood of yielding a live birth. The vast majority of published live births following the transfer of embryos with a mosaic result have been reported to be without phenotypic abnormality. However, many of these pregnancies have chosen to not perform prenatal diagnostic testing which limits our ability to understand the prevalence of mosaicism in newborns that result from the transfer of these embryos. To date, there has been at least one live birth of a newborn with mosaicism that resulted following the transfer of an embryo with a mosaic result.

Summary

While embryos with a mosaic result have the potential to result in a healthy live birth, the transfer of these embryos is not without risks, both known and unknown. Clinicians that utilize PGT-A with reporting of mosaic results must familiarize themselves with the current literature on outcomes following the transfer of mosaic embryos, and as more data emerges, recommendations and guidelines on this topic will likely continue to evolve. Patients that are considering the transfer of embryos with a mosaic result should understand the limitations of the current published outcome data and should receive extensive counseling both before and after the transfer of these embryos.

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References

Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance

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Authors and Affiliations

  1. The Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medical Center, 1305 York Avenue, New York, NY, 10021, USA

    Phillip A. Romanski

  2. Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, San Francisco, CA, USA

    Eduardo Hariton

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  1. Phillip A. Romanski
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  2. Eduardo Hariton
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Correspondence to Phillip A. Romanski.

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This article is part of the Topical Collection on Reproductive Endocrinology and Infertility (REI)

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Romanski, P.A., Hariton, E. Embryos with a Mosaic Result: the Known and Unknown Reproductive Potential. Curr Obstet Gynecol Rep 10, 71–76 (2021). https://doi.org/10.1007/s13669-021-00317-0

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