Abstract
Objective
To comprehensively describe current preimplantation genetic testing for aneuploidy
(PGT-A) practices and management of non-euploid embryos in Canada.
Methods
This was a cross-sectional study utilizing an online survey distributed by email to
all medical directors of fertility clinics with independent in vitro fertilization
(IVF) embryology laboratories. The survey was designed to determine practice patterns
regarding PGT-A usage; PGT-A reference laboratory, platform, and thresholds for classifying
embryos; and management of embryos classified as mosaic, inconclusive, or aneuploid.
Results
Twenty-five medical directors (69%) participated in the survey. The majority of clinics
(91%) offered PGT-A screening, with 45% of clinics offering PGT-A as routine screening.
The majority of clinics (90%) that offered PGT-A received mosaicism data; 61% of these
clinics had transferred mosaic embryos, and 94% would transfer mosaic embryos. Clinics
that performed ≥1000 IVF cycles annually were more likely to have transferred mosaic
embryos (100% vs. 45.5%; P = 0.043). The mean percentage of IVF cycles using PGT-A was lower in clinics that
had transferred mosaic embryos (12.3% vs. 30.4%; P = 0.033). Only 1 clinic had transferred an aneuploid embryo, but 2 other clinics
would consider this option. The majority of clinics (61%) that receive mosaicism data
would recommend noninvasive prenatal testing (NIPT) following mosaic embryo transfer,
with 22% of clinics indicating that this would be the only genetic test offered.
Conclusion
We report significant practice variation in PGT-A and management of non-euploid embryos
across Canada and highlight areas where consensus should be encouraged.
Résumé
Objectif
Décrire en détail les pratiques actuelles concernant les tests génétiques préimplantatoires
des aneuploïdies (TGP-A) et la gestion des embryons non euploïdes au Canada.
Méthodologie
Il s’agit d’une étude transversale réalisée à partir d’un sondage en ligne envoyé
par courriel à tous les directeurs médicaux de cliniques de fertilité avec laboratoire
indépendant de fécondation in vitro (FIV). Le sondage a été conçu pour déterminer
les habitudes de pratique concernant l’utilisation des TGP-A; le laboratoire de référence,
la plateforme utilisée et les seuils de classification des embryons relativement aux
TGP-A; et la gestion des embryons classés comme mosaïques, non concluants ou aneuploïdes.
Résultats
Au total, 25 directeurs médicaux (69 %) ont participé au sondage. La majorité des
cliniques (91 %) offrent le dépistage par TGP-A, et 45 % offrent les TGP-A comme dépistage
de routine. La majorité des cliniques (90 %) offrant les TGP-A reçoivent des données
sur le mosaïcisme; 61 % de ces cliniques avaient transféré des embryons en mosaïque;
et 94 % ont dit qu’ils transféreraient de tels embryons. Les cliniques qui effectuent
1 000 cycles de FIV ou plus par année étaient plus susceptibles d’avoir transféré
des embryons en mosaïque (100 % p/r à 45,5 %; p = 0,043). Le pourcentage moyen de cycles de FIV réalisés avec TGP-A était inférieur
dans les cliniques ayant transféré des embryons en mosaïque (12,3 % p/r à 30,4 %;
p = 0,033). Seulement 1 clinique avait transféré un embryon aneuploïde, mais 2 autres
envisageraient cette option. La majorité des cliniques (61 %) qui reçoivent des données
sur le mosaïcisme recommanderaient un test génomique prénatal non invasif (TGPNI)
après un transfert d’embryon en mosaïque, et 22 % des cliniques ont indiqué qu’il
s’agirait du seul test génétique offert.
Conclusion
Nous signalons une importante variation dans les pratiques concernant les TGP-A et
la gestion des embryons non euploïdes au Canada et nous soulignons les champs où il
y aurait lieu d’établir un consensus.
Keywords
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to Journal of Obstetrics and Gynaecology CanadaAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- Preimplantation genetic testing for aneuploidy: a Canadian Fertility and Andrology Society guideline.Reprod BioMed Online. 2021; 42: 105-116
- Preimplantation genetic screening: what is the clinical efficiency?.Fertil Steril. 2017; 108: 228-230
- Chromosome mosaicism in human embryos.Biol Reprod. 1994; 51: 373-379
- Clinical management of mosaic results from preimplantation genetic testing for aneuploidy (PGT-A) of blastocysts: a committee opinion.Fertil Steril. 2020; 114: 246-254
- Noninvasive preimplantation genetic testing for aneuploidy in spent medium may be more reliable than trophectoderm biopsy.Proc Natl Acad Sci U S A. 2019; 116: 14105
- Comprehensive chromosome screening is highly predictive of the reproductive potential of human embryos: a prospective, blinded, nonselection study.Fertil Steril. 2012; 97: 870-875
- Further evidence against use of PGS in poor prognosis patients: report of normal births after transfer of embryos reported as aneuploid.Fertil Steril. 2015; 104: e59
- Inconclusive chromosomal assessment after blastocyst biopsy: prevalence, causative factors and outcomes after re-biopsy and re-vitrification. A multicenter experience.Hum Reprod. 2018; 33: 1839-1846
- National mosaic embryo transfer practices: a survey.Am J Obstet Gynecol. 2018; 219 (602.e1–e7)
- Preimplantation genetic screening: results of a worldwide web-based survey.Reprod BioMed Online. 2017; 35: 693-700
- Worldwide live births following the transfer of chromosomally “abnormal” embryos after PGT/A: results of a worldwide web-based survey.J Assist Reprod Genet. 2019; 36: 1599-1607
Article info
Publication history
Published online: May 13, 2022
Accepted:
April 19,
2022
Received:
January 11,
2022
Footnotes
Disclosures: The authors declare they have nothing to disclose.
All authors have indicated they meet the journal’s requirements for authorship.
Identification
Copyright
© 2022 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.
