Received July 10, 2025
Accepted June 05, 2026

Objectives: Obesity in women is known to be associated with compromised ovarian function. The oocytes are characterized by elevated cytoplasmic oxidative stress, and poor cytoplasmic organization under such conditions, which might affect the tolerance of the oocytes to exogenous stresses such as freeze-thawing process. This study investigates the cryosusceptibility of oocytes derived from mice with high fat diet (HFD)-induced obesity. Methods: Three weeks old female mice were divided into the control group (fed with a normal chow diet) and the obese group (fed with HFD for 12 weeks). Oocytes from control and obese groups were subjected to vitrification and thawing. Post-thaw survival, reactive oxygen species (ROS) level, mitochondrial and endoplasmic reticulum (ER) distribution, ER stress and maturation potential of GV stage oocytes were assessed. Results: Despite increased lipid accumulation, and increased ROS level found in oocytes of obese mice, post-thaw survival rate of GV oocytes was comparable between the groups. However, obesity induced alterations in mitochondrial and ER distribution. Further, the MII oocytes derived from vitrified-thawed GV stage oocytes of obese mice had significantly higher percentage of oocytes with spindle defects. A significant increase in ER stress markers GRP78 and ATF4 was observed in frozen-thawed GV oocytes compared to control group. Conclusion: These findings suggest that maternal obesity does not significantly affect the cryosurvival of oocyte, it compromises oocyte quality post-vitrification, underscoring the need for optimized cryopreservation strategies in obese patients undergoing ART.