Summary: Researchers say stress may directly impact female fertility and ovarian reserve. Exposing female rats to scream sounds, researchers noted a decrease in estrogen and Anti-Mullerian hormone levels. Stress also reduced the number and quality of eggs, resulting in smaller litters. The findings shed light on the role stress may play in female reproduction.
Source: The Endocrine Society
Female rats exposed to a scream sound may have diminished ovarian reserve and reduced fertility, according to a small animal study published in the Endocrine Society’s journal, Endocrinology.
Ovarian reserve is the reproductive potential left within a woman’s two ovaries based on the number and quality of eggs. A woman is born with a finite number of eggs and her body cannot create any more.
Diminished ovarian reserve is the loss of normal reproductive potential in the ovaries due to a lower count or quality of the remaining eggs.
“We examined the effect of stress on ovarian reserve using a scream sound model in rats,” said Wenyan Xi, Ph.D., of the Second Affiliation Hospital of Xi’an Jiao Tong University in Xian, China. “We found that female rats exposed to the scream sound had diminished ovarian reserve and decreased fertility.”
The researchers used a scream sound model to investigate the effect of stress on ovarian reserve in female rats. They exposed female rats to a scream sound for 3 weeks and analyzed the effect on their sex hormones, the number and quality of their eggs and their ability to get pregnant and have babies after mating.
They found the scream sound decreased the rats’ estrogen and Anti-Mullerian hormone levels. Estrogen is a group of hormones that play an important role in growth and reproductive development, and Anti-Mullerian hormone is a hormone made by the ovaries which helps form reproductive organs.
The scream sound also lowered the number and quality of the women’s eggs and resulted in smaller litters.
“Based on these findings, we suggest stress may be associated with diminished ovarian reserve,” Xi said.
“It is important to determine an association between chronic stress and ovarian reserve because doing so may expand our appreciation of the limitations of current clinical interventions and provide valuable insight into the cause of diminished ovarian reserve.”
Other authors of this study include: Hui Mao, Haoyan Yao and Ruiting Shi of the Second Affiliation Hospital of Xi’an Jiao Tong University; and Zhiwei Cui of the First Affiliation Hospital of Xi’an Jiao Tong University in Xian, China.
Funding: The study received funding from the Natural Science Foundation of Shaanxi Provincial Department of Education.
Scream sound induced chronic psychological stress results in diminished ovarian reserve in adult female rat
It is well established that chronic psychological stress (PS) induces female reproductive dysfunction. However, the consequences of chronic PS exposure precisely targeting ovarian reserve are lacking.
In the present study, we employed a chronic scream sound-induced PS model to investigate the potential effect of pure psychosocial stressors on ovary reserve.
Female rats were subjected to scream sound stress, white noise or background for 3 weeks. Animals were euthanized by cervical dislocation after stress for collection of blood or ovary.
Sex hormones were analyzed by enzyme-linked immunosorbent assay (ELISA). The follicle number was examined by histopathology. Granulosa cell apoptosis of the ovaries was examined by in situ cell death detection kit. Finally, rats were mate with proven fertile male rats to study fertility parameters.
Female rats exposed to scream sound were presented with reduced weight gain and sucrose preference, while immobility time in forced swimming test (FST) and serum corticosterone (CORT) concentration were significantly increased.
Scream sound stress sequentially decreased plasma Anti-Mullerian hormone (AMH) and estradiol (E2) concentration, induced primordial and preantral follicles loss, augmented granulosa cell apoptosis in ovarian growing follicles, and eventually decreased litter sizes.
Based on these results we suggest that chronic PS induced loss of ovarian reserve by accelerated primordial follicle activation and destruction of growing follicles, which results in follicle depletion and decreased fertility.