PMID- 29945889
OWN - NLM
STAT- MEDLINE
DCOM- 20181105
LR  - 20181105
IS  - 1741-7899 (Electronic)
IS  - 1470-1626 (Linking)
VI  - 156
IP  - 1
DP  - 2018 Jul
TI  - Chromosomal analysis in IVF: just how useful is it?
PG  - F29-F50
LID - 10.1530/REP-17-0683 [doi]
AB  - Designed to minimize chances of genetically abnormal embryos, preimplantation 
      genetic diagnosis (PGD) involves in vitro fertilization (IVF), embryo biopsy, 
      diagnosis and selective embryo transfer. Preimplantation genetic testing for 
      aneuploidy (PGT-A) aims to avoid miscarriage and live born trisomic offspring and 
      to improve IVF success. Diagnostic approaches include fluorescence in situ 
      hybridization (FISH) and more contemporary comprehensive chromosome screening 
      (CCS) including array comparative genomic hybridization (aCGH), quantitative 
      polymerase chain reaction (PCR), next-generation sequencing (NGS) and 
      karyomapping. NGS has an improved dynamic range, and karyomapping can detect 
      chromosomal and monogenic disorders simultaneously. Mosaicism (commonplace in 
      human embryos) can arise by several mechanisms; those arising initially 
      meiotically (but with a subsequent post-zygotic 'trisomy rescue' event) usually 
      lead to adverse outcomes, whereas the extent to which mosaics that are initially 
      chromosomally normal (but then arise purely post-zygotically) can lead to 
      unaffected live births is uncertain. Polar body (PB) biopsy is the least common 
      sampling method, having drawbacks including cost and inability to detect any 
      paternal contribution. Historically, cleavage-stage (blastomere) biopsy has been 
      the most popular; however, higher abnormality levels, mosaicism and potential for 
      embryo damage have led to it being superseded by blastocyst (trophectoderm - TE) 
      biopsy, which provides more cells for analysis. Improved biopsy, diagnosis and 
      freeze-all strategies collectively have the potential to revolutionize PGT-A, and 
      there is increasing evidence of their combined efficacy. Nonetheless, PGT-A 
      continues to attract criticism, prompting questions of when we consider the 
      evidence base sufficient to justify routine PGT-A? Basic biological research is 
      essential to address unanswered questions concerning the chromosome complement of 
      human embryos, and we thus entreat companies, governments and charities to fund 
      more. This will benefit both IVF patients and prospective parents at risk of 
      aneuploid offspring following natural conception. The aim of this review is to 
      appraise the 'state of the art' in terms of PGT-A, including the controversial 
      areas, and to suggest a practical 'way forward' in terms of future diagnosis and 
      applied research.
CI  - (c) 2018 Society for Reproduction and Fertility.
FAU - Griffin, Darren K
AU  - Griffin DK
AD  - School of BiosciencesCentre for Interdisciplinary Studies of Reproduction, 
      University of Kent, Canterbury, UK d.k.griffin@kent.ac.uk.
FAU - Ogur, Cagri
AU  - Ogur C
AD  - Bahceci Genetic Diagnosis CenterIstanbul, Turkey.
AD  - Department of BioengineeringYildiz Technical University, Istanbul, Turkey.
LA  - eng
PT  - Journal Article
PT  - Review
PL  - England
TA  - Reproduction
JT  - Reproduction (Cambridge, England)
JID - 100966036
SB  - IM
MH  - Adult
MH  - *Comparative Genomic Hybridization
MH  - Embryo Culture Techniques
MH  - Female
MH  - *Fertilization in Vitro
MH  - Humans
MH  - Karyotyping
MH  - Mosaicism
MH  - Pregnancy
MH  - *Preimplantation Diagnosis
EDAT- 2018/06/28 06:00
MHDA- 2018/11/06 06:00
CRDT- 2018/06/28 06:00
PHST- 2017/11/13 00:00 [received]
PHST- 2018/03/23 00:00 [accepted]
PHST- 2018/06/28 06:00 [entrez]
PHST- 2018/06/28 06:00 [pubmed]
PHST- 2018/11/06 06:00 [medline]
AID - 156/1/F29 [pii]
AID - 10.1530/REP-17-0683 [doi]
PST - ppublish
SO  - Reproduction. 2018 Jul;156(1):F29-F50. doi: 10.1530/REP-17-0683.