Oocytes with Aggregates of Smooth Endoplasmic Reticulum May Not Affect Reproductive Outcomes in Split IVF-ICSI Insemination: A Retrospective Study

Yejuan Li¹Jia-Jia Hu¹Hui Lu¹Zhi-Yong Lu¹Jing-Jing Zhong¹Shi-Sen Shi^2*

• ¹Hainan Women and Children's Medical Center, Haikou, China
• ²Haikou Maternal and Child Health Hospital, Haikou, Hainan Province, China

Objective: To investigate the impact of smooth endoplasmic reticulum aggregates (SERa) in oocytes on embryological outcomes and clinical and neonatal outcomes during split IVF-ICSI cycles. Methods: A retrospective analysis was conducted using clinical data from January 2020 to December 2023 at the Reproductive Medicine Center of Hainan Women and Children's Medical Center. Patients were divided into SERa+ and SERa- cycles based on the visibility of SERa after the removal of cumulus cells. Basic patient characteristics, embryological outcomes, clinical and neonatal outcomes were compared between the two groups. Results: Compared to the SERa- cycles, the SERa+ cycles showed significantly higher levels of E2 on the day of hCG administration (P<0.01) and a significantly increased number of retrieved oocytes (P<0.01). In terms of embryological outcomes, the total D3 high-quality embryo rate was significantly higher in the SERa+ cycles (P<0.01). There was a significant increase in the D3 high-quality embryo rate for ICSI, but no difference in the D3 high-quality embryo rate for IVF. No significant differences were observed between the SERa+ and SERa- cycless in terms of βhCG positivity rate, clinical pregnancy rate, implantation rate, early miscarriage rate, live birth rate, preterm birth rate, newborn height, and weight (P>0.05). No congenital birth defects were found in either group. Conclusion: The occurrence of SERa in split IVF-ICSI cycles may be associated with increased E2 levels on hCG day, and the presence of SERa does not appear to affect in vitro fertilization, embryological, clinical, or neonatal outcomes.