title: The Effect of Prolonged Culture of Chromosomally Abnormal Human Embryos on The Rate of Diploid Cells.
abstract: BACKGROUND
  A decrease in aneuploidy rate following a prolonged co-culture of human blastocysts has been reported. As co-culture is not routinely used in assisted reproductive technology, the present study aimed to evaluate the effect of the prolonged single culture on the rate of diploid cells in human embryos with aneuploidies.
  
  
  METHODS
  In this cohort study, we used fluorescence in situ hybridi- zation (FISH) to reanalyze surplus blastocysts undergoing preimplantation genetic diagnosis (PGD) on day 3 postfertilization. They were randomly studied on days 6 or 7 following fertilization.
  
  
  RESULTS
  Of the 30 analyzed blastocysts, mosaicism was observed in 26(86.6%), while 2(6.7%) were diploid, and 2(6.7%) were triploid. Of those with mosaicism, 23(88.5%) were determined to be diploid-aneuploid and 3(11.5%) were aneuploid mosaic. The total frequency of embryos with more than 50% diploid cells was 33.3% that was lower on day 7 in comparison with the related value on day 6 (P<0.05); however, there were no differences when the embryos were classified according to maternal age, blastocyst developmental stage, total cell number on day 3, and embryo quality.
  
  
  CONCLUSIONS
  Although mosaicism is frequently observed in blastocysts, the prolonged single culture of blastocysts does not seem to increase the rate of normal cells.
authors.affiliation: Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran; Department of Developmental Biology, University of Science and Culture, Tehran, Iran.
authors.forename: Masood
authors.initials: M
authors.lastname: Bazrgar
authors.affiliation: Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Gourabi
authors.affiliation: Department of Embryology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors.forename: Poopak
authors.initials: P
authors.lastname: Eftekhari-Yazdi
authors.affiliation: Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors.forename: Hamed
authors.initials: H
authors.lastname: Vazirinasab
authors.affiliation: Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Fakhri
authors.affiliation: Department of Embryology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Hassani
authors.affiliation: Department of Epidemiology and Reproductive Health, Reproductive Epidemiology Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors.forename: Mohamad
authors.initials: M
authors.lastname: Chehrazi
authors.affiliation: Department of Embryology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors.forename: Mojtaba Rezazadeh
authors.initials: MR
authors.lastname: Valojerdi
keywords: Aneuploidy; Blastocyst; Mosaicism; Self-Correction