O-180 What is the true potential of 1PN embryos? A report on utilisation and live birth rates following PGT-A and biparental testing

Abstract Study question What is the developmental potential of monopronuclear (1PN) embryos, and does allowing their use only after confirming biparental inheritance offer a clinical solution for them? Summary answer 1PN embryos demonstrate clear utilisation, euploidy, live birth rates, that warrant routine culture, following testing, in setting. known already Embryos displaying single pronuclei are widely regarded to be abnormal not suitable use. It therefore common practice discard these fertilisation check. However, have shown ability normal blastocyst development, albeit at decreased rate, produce births. To bridge gap between discarding an “abnormal” embryo, knowledge it can result birth, our clinic utilises PGT-A with testing assess fitness embryo transfer. design, size, duration A retrospective analysis was performed 5010 derived from IVF (2612) or ICSI (2398) insemination Genea clinics across Australia January 2017 November 2022. Blastocyst parental inheritance, pregnancy, rates were analysed. Participants/materials, setting, methods defined as being by appearance one check 16-18 hours post insemination. Time lapse footage reviewed on day 3 culture eliminate late second pronucleus. Suitable underwent trophectoderm biopsy testing. Only euploid confirmed available patients frozen Main results role chance found significantly lower development 17.4% compared 33.7% (p < 0.0001). The utilisation rate also 8.1% vs 21.2% showed higher euploidy PGA-T 50.9% 37.9% Uniparental indication caused parthenogenesis, observed 6.7% total tested, having considerably 1.8% 20.5% There no significant difference 2 groups pregnancy births, transfer, 58.6% 62.9% = 0.6) 39.6% 45.7% 0.5) respectively. These levels comparable normally fertilised (2PN) same time period. During study period there been 175 transferred has resulted 69 births otherwise would discarded. Limitations, reasons caution timelapse imaging opposed may play type identified each group. Wider implications findings This demonstrates all lab conjunction appropriate should re-evaluated. Trial registration number not-applicable