title: The clinical effectiveness of preimplantation genetic diagnosis for aneuploidy in all 24 chromosomes (PGD-A): systematic review.
abstract: OBJECTIVE
  Is preimplantation genetic diagnosis for aneuploidy (PGD-A) with analysis of all chromosomes during assisted reproductive technology (ART) clinically and cost effective?
  
  
  CONCLUSIONS
  The majority of published studies comparing a strategy of PGD-A with morphologically assessed embryos have reported a higher implantation rate per embryo using PGD-A, but insufficient data has been presented to evaluate the clinical and cost-effectiveness of PGD-A in the clinical setting.
  
  
  BACKGROUND
  Aneuploidy is a leading cause of implantation failure, miscarriage and congenital abnormalities in humans, and a significant cause of ART failure. Preclinical evidence of PGD-A indicates that the selection and transfer of euploid embryos during ART should improve clinical outcomes.
  
  
  METHODS
  A systematic review of the literature was performed for full text English language articles using MEDLINE, EMBASE, SCOPUS, Cochrane Library databases, NHS Economic Evaluation Database and EconLit. The Downs and Black scoring checklist was used to assess the quality of studies. Clinical effectiveness was measured in terms of pregnancy, live birth and miscarriage rates.
  
  
  METHODS
  Nineteen articles meeting the inclusion criteria, comprising three RCTs in young and good prognosis patients and 16 observation studies were identified. Five of the observational studies included a control group of patients where embryos were selected based on morphological criteria (matched cohort studies).
  
  
  RESULTS
  Of the five studies that included a control group and reported implantation rates, four studies (including two RCTs) demonstrated improved implantation rates in the PGD-A group. Of the eight studies that included a control group, six studies (including two RCTs) reported significantly higher pregnancy rates in the PGD-A group, and in the remaining two studies, equivalent pregnancies rates were reported despite fewer embryos being transferred in the PGD-A group. The three RCTs demonstrated benefit in young and good prognosis patients in terms of clinical pregnancy rates and the use of single embryo transfer. However, studies relating to patients of advanced maternal age, recurrent miscarriage and implantation failure were restricted to matched cohort studies, limiting the ability to draw meaningful conclusions.
  
  
  CONCLUSIONS
  Relevant studies may have been missed and findings from RCTs currently being undertaken could not be included.
  
  
  CONCLUSIONS
  Given the uncertain role of PGD-A techniques, high-quality experimental studies using intention-to-treat analysis and cumulative live birth rates including the comparative outcomes from remaining cryopreserved embryos are needed to evaluate the overall role of PGD-A in the clinical setting. It is only in this way that the true contribution of PGD-A to ART can be understood.
authors.affiliation: National Perinatal Epidemiology and Statistics Unit, School of Women's and Children's Health, University of New South Wales (UNSW), Level 2, McNevin Dickson Building, Randwick Hospitals Campus, Sydney 2031, Australia evelyn.lee@unsw.edu.au.
authors.forename: Evelyn
authors.initials: E
authors.lastname: Lee
authors.affiliation: IVF Australia Pty Ltd, 176 Pacific Highway, Greenwich, Sydney 2065, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Illingworth
authors.affiliation: Melbourne IVF, Victoria Parade, East Melbourne, VIC 3002, Australia.
authors.forename: Leeanda
authors.initials: L
authors.lastname: Wilton
authors.affiliation: National Perinatal Epidemiology and Statistics Unit, School of Women's and Children's Health, University of New South Wales (UNSW), Level 2, McNevin Dickson Building, Randwick Hospitals Campus, Sydney 2031, Australia.
authors.forename: Georgina Mary
authors.initials: GM
authors.lastname: Chambers
mesh_terms: D000782:Aneuploidy; D001723:Birth Rate; D025063:Chromosome Disorders / Q000175:diagnosis* / Q000191:economics / Q000517:prevention & control; D003362:Cost-Benefit Analysis; D019317:Evidence-Based Medicine; D005191:Family Characteristics; D005260:Female; D006801:Humans; D008297:Male; D011247:Pregnancy; D018873:Pregnancy Rate; D019836:Preimplantation Diagnosis / Q000009:adverse effects / Q000191:economics; D027724:Reproductive Techniques, Assisted / Q000009:adverse effects / Q000191:economics
keywords: aneuploidy; assisted reproductive technologies; embryo selection; preimplantation genetic diagnosis; preimplantation genetic screening