P-048 Morphokinetic analysis and implantation prediction of embryos derived from oocytes microinjected with Artificial Intelligence (AI) real-time assessed sperm
Authors: Beltrán Torregrosa D , Carrión-Sisternas L , Carrión T , Gámiz P , Conversa L , Martin E , Piluso C , Meseguer M 
Published: July 2024

Abstract

Study question
Is embryo morphokinetic development affected by sperm quality assessed real time during Intracytoplasmic Sperm Injection (ICSI)?

Summary answer
Embryos derived from oocytes microinjected with low-quality sperm, analyzed by an AI-tool, exhibit a sluggish pace and a diminished potential for successful implantation.

What is known already
The study of embryo morphokinetics provides insights into the temporal aspects of cell division, which are pivotal for successful implantation. Key parameters such as time of division to 3 cells (t3), time to division to 5 cells (t5), time between division to 3 cells and subsequent division to 4 cells (s2) and duration of cell cycle two, i.e. time between division to 2 cells and division to 3 cells (cc2) are closely associated with implantation potential. Monitoring these markers allows clinicians to select embryos with optimal developmental trajectories, improving the chances of successful implantation and ultimately leading to healthier pregnancies.

Study design, size, duration
That is a single-centre and non-intervention study of 60 ICSI cycles. Seminal samples were assessed real-time with Sperm identification (SiD) software (v1.0, IVF2.0, LTD). Microinjected oocytes were maintained in culture in time-lapse incubators (EmbryoScope or EmbryoScope Plus). Injected sperm and their corresponding oocytes were individually followed-up to assess early embryo morphokinetics: t3, t5, s2, cc2 (273 total blastocysts) in a four-month period.

Participants/materials, setting, methods
Sixty ICSI cycles (35 from own oocytes and 25 from egg donation) were studied.418 sperm were assessed with SiD and classified as ‘low’, ‘medium’, ‘good’ or ‘best’, according to their motility parameters. Early embryonic morphokinetics were studied focusing on t3, t5, s2 and cc2 times. Ranges related with best implantation potential were studied according to previous works of our group: t3(34-40h), t5 (45-55h), cc2 (9-12h) and s2 (≤0,76h).

Main results and the role of chance
No discernible differences were observed in the parameters t3 and t5 among embryos within each sperm quality group. However, significant differences were identified in s2 and cc2 metrics between embryos of distinct sperm quality groups. Specifically, oocytes subjected to microinjection with ‘best’ or ‘good’ sperm exhibited an optimal average cc2 length (10.49 ± 5.12), in stark contrast to embryos derived from oocytes microinjected with ‘medium’ or ‘low’ sperm, which manifested an acelerated developmental pace (8.73 ± 5.55) (p &lt; 0.05). Furthermore, embryos from the ‘best’ and ‘good’ groups displayed significantly shorter s2 lengths (1.16 ± 1.98 and 1.03 ± 1.62) compared to embryos from the ‘low’ group (2.73 ± 3.96). The latter exhibited an extended duration between the 3-cell division and subsequent division to 4 cells (p &lt; 0.05). These findings lead us to infer that embryos arising from oocytes microinjected with ‘best’ or ‘good’ sperm possess superior implantation potential compared to those originating from oocytes microinjected with ‘medium’ or ‘low’ sperm, as indicated by SiD scores. The latter cohort appears to exhibit an alterated morphokinetic development and diminished implantation potential.

Limitations, reasons for caution
This project is limited by its retrospective and single-centre nature. In addition, studying later embryo morphokinetics parameters could provide a better description of embryo development and its relation with sperm quality assessed real-time. Finally, sperm morphology should also be included in SiD software because of its relation with reproductive success.

Wider implications of the findings
Selection of high-quality sperm to microinject into the oocytes, supported by real-time analysis, could contribute to improved morphological and kinetic characteristics of embryos, potentially increasing the chances of success in assisted reproductive procedures. In addition, it provides an opportunity to reduce subjectivity and inter-user variability of ICSI procedure.

Trial registration number
Not applicable