ORIGINAL ARTICLE: GENETICS Chromosomal abnormalities in embryos from couples with a previous aneuploid miscarriage Remohí, M.D., Ph.D.,d Nasser Al-Asmar, M.Sc.,a,b Vanessa Peinado, M.Sc.,a María Vera, M.Sc.,a Jose d c,d Antonio Pellicer, M.D., Ph.D., Carlos Simon, M.D., Ph.D., Terry Hassold, Ph.D.,e and Carmen Rubio, Ph.D.a,b a Preimplantation Genetic Diagnosis Unit, Iviomics, Paterna, Spain; b Preimplantation Genetic Diagnosis Unit, Instituto Valenciano de Infertilitad, IVI-Valencia, Valencia, Spain; c Scientific Director, Iviomics, Paterna, Spain; d Medical Reproduction Unit, Instituto Valenciano de Infertilidad, IVI-Valencia, Valencia, Spain; and e School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, Washington Objective: To compare the incidence of chromosomal abnormalities in preimplantation embryos from couples undergoing preimplantation genetic screening (PGS) after previous aneuploid miscarriage after either natural conception (NC) or assisted reproductive technology (ART) versus fertile couples who underwent PGS for sex-linked diseases as a control group Design: Retrospective study Setting: IVF clinic Patient(s): Patients with previous aneuploid conception undergoing PGS Intervention(s): Embryo biopsy, fluorescence in situ hybridization Main Outcome Measure(s): Embryo aneuploidy rates and pregnancy and implantation rates in couples with a previous aneuploidy for autosomes or sex chromosomes Result(s): The overall rates of chromosomal abnormalities in groups with previous autosomal aneuploidy were significantly higher compared with the control group (67.8% for those whose previous aneuploidy arose after NC and 65.8% for those previously arising after ART, vs 34.0%) No significant differences were observed in those with previous sex chromosome abnormalities compared with control subjects Within couples with previous aneuploidies after NC, no difference existed in the incidence of chromosomal abnormalities compared with the ART groups Clinical outcomes were better (trend) in patients with previous autosomal aneuploidy after NC Conclusion(s): In preimplantation embryos, the incidence of chromosomal abnormalities due to a previous aneuploid miscarriage after either NC or ART is significantly higher than in the control group Furthermore, this incidence is higher when the previous aneuploidy was for autosomes; PGS is recommended in these couples (Fertil SterilỊ 2012;98:145–50 Ĩ2012 by American Society for Reproductive Medicine.) Key Words: Preimplantation genetic screening, fluorescence in situ hybridization, chromosomal abnormalities, natural conceptions, assisted reproductive technology N o fewer than 10% of clinically recognized human pregnancies end in spontaneous abortion A large proportion, if not a majority, of these involve chromosomally abnormal conceptuses In fact, estimated rates of chromosomal abnormality in spontaneous abortions arising from natural conceptions (NC) vary from 47.9% to 83.0% (1–5) The most common chromosome abnormality in humans is aneuploidy, i.e., a missing (monosomy) or extra (trisomy) chromosome Aneuploidy is the main genetic cause of miscarriages (6, 7) A few autosomal trisomies (13, 18, and 21) and sex chromosome aneuploidies (45,X; 47,XXY; 47,XXX; or 47,XYY) are compatible with life, but they typically result in serious congenital malformations and/or Received December 22, 2011; revised March 15, 2012; accepted March 17, 2012; published online April 21, 2012 N.A.-A has nothing to disclose V.P has nothing to disclose M.V has nothing to disclose J.R has nothing to disclose A.P has nothing to disclose C.S has nothing to disclose T.H has nothing to disclose C.R has nothing to disclose Reprint requests: Nasser Al-Asmar, M.Sc., Iviomics, Preimplantation Genetic Diagnosis Unit, Parc ncia, Catedra tico Agustín Escardino Street n 9, Biotec Building 2, Científic Universitat de Vale lab 2.10, 46980, Paterna, Spain (E-mail: nasser@iviomics.com) Fertility and Sterility® Vol 98, No 1, July 2012 0015-0282/$36.00 Copyright ©2012 American Society for Reproductive Medicine, Published by Elsevier Inc doi:10.1016/j.fertnstert.2012.03.035 VOL 98 NO / JULY 2012 cognitive or behavioral abnormalities; indeed, aneuploidy is the most frequent known cause of mental retardation and congenital birth defects in humans (6–8) As a group, sex chromosome aneuploidies are the leading type of chromosome abnormality in newborns (6, 8) Compared with sex chromosomes, autosomal aneuploidies produce more adverse phenotypic effects and are less compatible with an ongoing pregnancy (9) The increasing use of assisted reproductive technology (ART) has generated concern about possible increases in chromosome abnormalities in ART-initiated pregnancies, but the data are equivocal Some studies found 145 ORIGINAL ARTICLE: GENETICS no statistical difference in the total frequency of chromosomal abnormalities after a pregnancy arising by NC or ART [specifically, in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI)] (4, 5, 10, 11) However, the type of chromosomal abnormality may differ: Bettio et al (2008) described a twofold increase in polyploidy after ART compared with NC, whereas Martínez et al (2010) described an increase in the incidence of monosomy X and a decrease in polyploidies in miscarriages after ICSI (4, 5) Furthermore, within ART itself, the total aneuploidy rate between ICSI and IVF is not significantly different (4, 10–12), but sex chromosome aneuploidy is more frequent in ICSI-related pregnancies than in pregnancies associated with conventional IVF (10–12) Additionally, studies have reported that the risk of fetal aneuploidy increases in couples with previous spontaneous abortions or aneuploid conceptions due to both autosomes and sex chromosomes (13–17) Women who have had a previous trisomic pregnancy, particularly those