When next-generation sequencing-based preimplantation genetic testing for aneuploidy (PGT-A) yields an inconclusive report: diagnostic results and clinical outcomes after re biopsy

J Assist Reprod Genet. 2019 Oct;36(10):2103-2109. doi: 10.1007/s10815-019-01550-6. Epub 2019 Aug 30.

Abstract

Purpose: To describe diagnostic results following re-biopsy of blastocysts with inconclusive results on preimplantation genetic screening for aneuploidy (PGT-A) and to evaluate the reproductive potential of re-biopsied blastocysts.

Methods: This retrospective cohort study included all trophectoderm biopsies submitted for PGT-A by a large in vitro fertilization center to a single genetics laboratory from June 2016 to October 2018. PGT-A was performed using next-generation sequencing (NGS). No-result blastocysts that underwent re-biopsy were subsequently classified as euploid, aneuploid, mosaic/segmental, or no-result. Ongoing pregnancy and clinical loss rates were assessed following transfer of re-biopsied blastocysts. Logistic regressions were conducted to account for age and blastocyst morphology.

Results: Of the trophectoderm biopsies submitted for PGT-A, 635/25,199 (2.5%) were categorized as no-result. Those that underwent re-biopsy (n = 250) had a 95.2% diagnostic rate with 140 (56.0%) receiving euploid diagnoses. Thirty-six re-biopsied blastocysts deemed euploid were subsequently transferred, resulting in 18 (50.0%) ongoing pregnancies and 5 (13.9%) clinical losses. After adjusting for age and blastocyst morphology, there remained a lower ongoing pregnancy rate and a trend towards higher clinical loss rate following transfer of a re-biopsied blastocyst. When compared to blastocysts that underwent the same number of vitrification-warming cycles but only one biopsy, there were no differences in outcomes.

Conclusions: Failure to obtain an analytical result does not change the probability that a given blastocyst is euploid. Pregnancy outcomes following transfer of re-biopsied blastocysts are favorable, but further data must be accrued for an adequately powered comparison with outcomes after transfer of blastocysts biopsied once.

Keywords: Blastocyst; Inconclusive results; Next-generation sequencing; Preimplantation genetic testing for aneuploidy; Re-biopsy; Trophectoderm biopsy.

MeSH terms

  • Adult
  • Aneuploidy*
  • Biopsy
  • Blastocyst / cytology*
  • Blastocyst / metabolism
  • Ectoderm / cytology*
  • Ectoderm / metabolism
  • Female
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Logistic Models
  • Pregnancy
  • Preimplantation Diagnosis*