Transfers of lower quality embryos based on morphological appearance result in appreciable live birth rates: a Canadian center’s experience

Abstract

Objective: To determine the reproductive outcomes resulting from transfer of lower-grade blastocysts to support the practice of cryopreserving and transferring lower-grade embryos. Design: Retrospective chart review. Setting: Single infertility center. Patient(s): Women who have undergone a fresh (n ¼ 570) or frozen (n ¼ 885) transfer of a single blastocyst embryo between December 2013 and December 2018. Intervention(s): None. Main Outcome Measure(s): The primary outcome was live birth rate. The secondary outcomes included implantation rate, ongoing pregnancy rate, associations with inner cell mass (ICM) and trophectoderm epithelium (TE) grades determined by morphological assessment, and antenatal/perinatal complications. Results: Reproductive outcomes directly correlated with embryo quality. Transfers of AA embryos resulted in a 41.4% live birth rate compared to 31.1% for BB embryos and 13.3% for CC embryos. The TE grade was significantly associated with the live birth rate. Embryos with a TE grade of ''B'' had an odds ratio of 0.677 and embryos with a TE grade of ''C'' had an odds ratio of 0.394 compared to embryos with a TE grade of ''A'' for live birth. Conclusion: Embryos with a TE ''C'' grade should be considered for transfer and cryopreservation, as they are shown to result in appreciable live birth rates. Such treatment should involve a thorough discussion with patients, however, as these live birth rates are significantly lower than those associated with higher-grade embryos.

Cumulative live birth rate in women aged ≤37 years after in vitro fertilization with or without preimplantation genetic testing for aneuploidy: a Society for Assisted Reproductive Technology Clinic Outcome Reporting System retrospective analysis

“…Furthermore, embryos of insufficient morphologic grade may be discarded before biopsy, lowering the total number of embryos available for transfer. Data suggest that embryos of lower morphologic grade do have appreciable live birth rates and should be considered for transfer (14). In a recent review, Kemper et al (15) evaluated randomized controlled trials comparing IVF with and without PGT-A and found that only 2 trials examined the CLBRs per started cycle.…”

Preimplantation genetic testing is not a preferred recommendation for patients with X chromosome abnormalities

“…Although a similar cancellation rate was observed between the two groups before the first transfer cycle, the oocyte utilisation rate in the conventional IVF/ICSI group significantly outweighed that in the PGT group, indicating that more embryos were available for further transfer. It has been reported that a proportion of the discarded embryos, due to poor morphological evaluation for blastocyst biopsy or cryopreservation, could also result in euploid newborns ( Lai et al , 2020 ). Further embryo loss during PGT process would further reduce the oocyte utilisation rate.…”

Blastocyst quality and reproductive and perinatal outcomes: a multinational multicentre observational study

“…While existing guidelines and consensus ( Alpha Scientists in Reproductive Medicine and ESHRE Special Interest Group of Embryology, 2011 ) do not recommend discarding low-grade blastocysts ( De los Santos et al , 2016 ; Morbeck, 2017 ; Practice Committees of the American Society for Reproductive Medicine (ASRM) and the Society for Reproductive Biologists and Technologists (SRBT), 2022 ), some clinics across the world routinely discard low-grade blastocysts as a matter of policy ( Rubio et al , 2014 ; Comstock et al , 2015 ; Munch et al , 2015 ; Lai et al , 2020 ).…”