Follicular fluid meiosis activating sterol supplementation enhances oocyte maturation and fertilization in a microfluidic system: A lab trial study.

Background: In vitro maturation (IVM) is a promising technique in assisted reproductive technologies, offering benefits such as reducing the risk of ovarian hyperstimulation syndrome.

Objective: This study aimed to evaluate the effects of timed follicular fluid meiosis-activating sterol (FF-MAS) supplementation on the IVM of germinal vesicle oocytes using a dynamic microfluidic system.

Materials and methods: In this lab trial study, 266 germinal vesicle oocytes were collected from the Infertility Center of Fatemieh hospital, Hamedan, Iran between June 2023 and January 2024. The oocytes were allocated into 3 groups for dynamic microfluidic culture. Each group received culture medium at a flow rate of 0.36 µL/min for 24 hr through inlet A and FF-MAS supplementation through inlet B for 1, 2, and 6 hr. The study evaluated maturation and fertilization rates, embryo development, and mitochondrial status, which was assessed using the JC-1 mitochondrial membrane potential assay.

Results: Maturation rates were significantly higher in the medium-term FF-MAS exposure (MTG) and long-term FF-MAS exposure groups compared to the short-term FF-MAS group (STG) (p $<$ 0.05). Fertilization rates were also higher in the MTG and long-term FF-MAS group compared to the STG (p $<$ 0.05). Embryo formation rates and the proportion of good-quality embryos were higher in the MTG compared to the STG (100% vs. 75%; p = 0.03) and (83.3% vs. 33.3%; p = 0.01), respectively. Mitochondrial peripheral distribution was significantly higher in the MTG than in the STG (p = 0.04).

Conclusion: Optimizing FF-MAS exposure duration enhances IVM efficiency, offering a promising strategy to increase oocyte utilization in in vitro fertilization programs.