Pregnancy after rebiopsy and vitrification of blastocysts following allele dropout after day 3 biopsy

Objective To report a clinical pregnancy after rebiopsy and vitrification of blastocysts following allele dropout (ADO) of biopsied day 3 embryos. Design Case report. Setting Private center. Patient(s) Thirty-year-old woman and her 33-year-old husband who carries the single-gene condition paraganglioma. Intervention(s) In vitro fertilization with day 3 embryo biopsy–ET–blastocyst biopsy and vitrification–subsequent frozen ET cycle. Main Outcome Measure(s) Results from preimplantation genetic diagnosis and pregnancy results after fresh and frozen ETs. Result(s) Nineteen oocytes were retrieved of which 13 were mature and 12 fertilized. Eleven embryos were biopsied on day 3: two were normal, five were affected, and four exhibited ADO. The two normal blastocysts were transferred, and three of the ADO blastocysts were biopsied and sent for reanalysis. The biopsied blastocysts were vitrified. No pregnancy resulted from the fresh ET. One of the biopsied blastocysts was normal, one received no result, and one exhibited ADO. A singleton clinical pregnancy resulted from a subsequent frozen ET of the thawed biopsied normal blastocyst. Conclusion(s) Rebiopsy and vitrification of blastocysts could be used in cases of ADO or lack of results after day 3 embryo biopsy.