Effects of Ovarian Gonadotropin Stimulation under Conditions of Chronic Psychosocial Stress on the Quality of Murine Oocytes

Chronic psychosocial stress can negatively affect the female reproductive system. Meanwhile, the effect of ovarian stimulation with gonadotropins during stress on the quality of oocytes remains poorly studied. This work was aimed to investigate the effects of chronic psychosocial stress on the quality of murine cumulus-oocyte complexes under the natural estrus cycle, as well as during the ovarian stimulation with exogenous gonadotropins, which is an important part of modern assisted reproductive technologies. Here we demonstrate that psychosocial stress does not affect the number of ovulating oocytes but deteriorates their quality, i.e. reduces the percentage of mature oocytes. In addition, stressed mice exhibited an enhanced accumulation of reactive oxygen species (ROS) in oocytes, accompanied by an increased apoptosis level in cumulus cells. Hormonal stimulation of the ovaries with gonadotropins alleviates the negative changes associated with psychosocial stress, normalizing ROS overproduction in oocytes and reducing apoptosis levels in cumulus cells.