title: Delayed intracytoplasmic sperm injection (ICSI) with trophectoderm biopsy and preimplantation genetic screening (PGS) show increased aneuploidy rates but can lead to live births with single thawed euploid embryo transfer (STEET).
abstract: OBJECTIVE
  The aim of this study was to report the results of IVF with trophectoderm biopsy and preimplantation genetic screening (PGS) following delayed intracytoplasmic sperm injection (ICSI).
  
  
  METHODS
  Patients undergoing IVF with PGS and delayed ICSI were included in the study. Indications for delayed ICSI included absent or poor fertilization via standard insemination or more than 50 % immature oocytes, noted post-cumulus stripping for standard ICSI procedure. Delayed ICSI was performed the day after retrieval due to absent or poor fertilization. The immature oocytes were kept in extended culture, and if demonstrated maturity, ICSI was performed. Primary outcome included fertilization rate and blastocyst stage formation, defined by the number of blastocysts for biopsy. Secondary outcome included aneuploidy rate and pregnancy outcomes following single thawed euploid embryo transfers (STEET).
  
  
  RESULTS
  Sixteen patients with delayed ICSI were included in the study. Twelve were due to poor fertilization and four secondary to immature oocytes. A total of 219 oocytes were retrieved; ten were frozen upon patient request, 168 had standard insemination, and 13 had routine ICSI on the day of retrieval. A total of 129 oocytes underwent delayed ICSI. Sixty-three (49 %) fertilized, 19 (14.7 %) reached blastocysts for biopsy; fivw of which were chromosomally normal (26.3 %). Three patients underwent STEET of a delayed ICSI embryo; all three resulted in live births, including one embryo biopsied on day 8 of development.
  
  
  CONCLUSIONS
  Fertilization failure or an excessive proportion of immature oocytes in an IVF cycle, necessitating delayed ICSI, showed equivalent fertilization and blast formation rates. With the implementation of trophectoderm biopsy and PGS, these embryos can lead to healthy live born babies.
authors.affiliation: New York University Fertility Center, 660 First Avenue 5th floor, New York, NY, 10016, USA. nidhee.mathur@nyumc.org.
authors.forename: Nidhee M
authors.initials: NM
authors.lastname: Sachdev
authors.affiliation: New York University Fertility Center, 660 First Avenue 5th floor, New York, NY, 10016, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Grifo
authors.affiliation: New York University Fertility Center, 660 First Avenue 5th floor, New York, NY, 10016, USA.
authors.forename: Frederick
authors.initials: F
authors.lastname: Licciardi
mesh_terms: D000328:Adult; D000782:Aneuploidy; D001706:Biopsy; D001755:Blastocyst; D047108:Embryonic Development / Q000235:genetics*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D050498:Live Birth / Q000235:genetics; D009865:Oocytes / Q000254:growth & development; D011247:Pregnancy; D011256:Pregnancy Outcome; D019836:Preimplantation Diagnosis; D056826:Single Embryo Transfer; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods
keywords: Delayed; Fertilization; Fertilization in vitro; Intracytoplasmic; Sperm injection