Tiềm năng phát triển của hợp tử một tiền nhân nuôi cấy bằng tủ theo dõi phôi liên tục

In assisted reproductive technologies (ART), particularly in vitro fertilization (IVF), the assessment and utilization of zygotes with abnormal pronuclear (PN) configurations, such as one pronucleus (1PN) zygotes, remain a critical challenge. While conventionally 2PN zygotes are deemed normal and prioritized for embryo transfer, 1PN zygotes have historically been considered aberrant due to concerns about aneuploidy and often discarded. However, emerging evidence suggests that a subset of these 1PN zygotes may possess viable developmental potential, capable of leading to healthy live births. Therefore, evaluating the developmental competence of 1PN zygotes, especially when cultured under advanced time-lapse monitoring systems, is crucial for optimizing IVF outcomes and expanding treatment options for patients with limited embryo availability.

Embryologists, reproductive endocrinologists, fertility clinicians, and researchers in assisted reproductive technologies (ART) aiming to optimize embryo selection and improve IVF success rates.

This retrospective study investigates the developmental potential of one pronuclear (1PN) zygotes compared to two pronuclear (2PN) zygotes generated via intracytoplasmic sperm injection (ICSI) and cultured using a time-lapse system. The research involved 126 1PN and 898 2PN zygotes from 110 couples undergoing IVF at Tam Anh General Hospital between May 2022 and September 2024. The primary objective was to compare cleavage rates, blastulation rates, and embryo quality between these two groups to inform clinical decision-making. Results indicated that 1PN zygotes exhibited significantly lower day 3 cleavage rates (88.9% vs. 98.9%, p < 0.001) and a reduced proportion of good-quality day 3 embryos (31.3% vs. 58.9%, p < 0.001) compared to 2PN zygotes. Similarly, the blastulation rate was considerably lower for 1PN zygotes (21.4% vs. 67.1%, p < 0.001). However, a crucial finding was that among the embryos that successfully reached the blastocyst stage, the morphological quality of 1PN-derived blastocysts was comparable to that of 2PN-derived blastocysts (good-quality blastocysts: 50.0% for 1PN vs. 52.2% for 2PN; p > 0.05). This suggests that while 1PN zygotes have a lower potential for initial development and blastocyst formation, those that do progress maintain the capacity to form high-quality blastocysts. The study emphasizes that 1PN zygotes should not be routinely discarded but rather cultured to the blastocyst stage, particularly in cases of limited embryo availability, to maximize patient chances for successful IVF outcomes. This approach could significantly improve the utilization of embryos and enhance treatment efficacy for infertility.