P-137 pronuclear characteristics and chromosomal constitutions of mono-pronuclear zygotes

Abstract Study question Limited studies have explored the correlation between pronuclear characteristics, developmental potential, and genetic constitution of mono-pronuclear (1PN) zygotes. Summary answer Those 1PN zygotes developed into blastocysts unique characteristics significantly higher rate diploidy euploidy in comparison with arrested embryos. What is known already It has been reported that similar morphokinetic features to two-pronuclear (2PN) Cytogenetic analyses reveal some embryos a normal chromosomal constitution. design, size, duration This retrospective cohort study included from December 2021 September 2022 (n = 388). Participants/materials, setting, methods Patients who underwent IVF or intracytoplasmic sperm injection (ICSI) Women Children’s Hospital Chongqing Medical University were recruited. Only cultured time-lapse incubators oocyte retrieval day included. The including area diameter pronuclear, number nuclei, distance near-polar body (DPNP), constitutions investigated. Main results role chance overall blastocyst formation good-quality rates 22.94% 16.24%, lower than 2PN (63.25% 50.23%, respectively, P 0.000). Compared embryos, showed larger (752.57 ± 131.53 vs. 653.65 116.58, 0.000), longer (30.10 2.90 27.28 2.83, greater nuclei (11.92 4.06 7.72 3.07, shorter DPNP (13.73 8.65 24.20 13.51, Of tested was (66.67% 11.76%, which also IVF-1PN ICSI-1PN (75.44% 25.00%, 0.001). Limitations, reasons for caution investigated only limited small sample size might weaken conclusions. In addition, part by NGS, inherent limitations because it could not find uniparental diploidy. Wider implications findings blastocysts, especially zygotes, high rates. utility potentially beneficial patients without other viable Trial registration Science Technology Committee (grant number: CSTB2022NSCQ-MSX0253), Health 2021MSXM108), Yuzhong District 20190143), 2021YJQN07).