Stress has been reported to cause infertility and miscarriages. A new study has found that shutting down a single gene may be able to prevent these effects. The study was published on January 12 in the journal eLife by researchers at the University of California, Berkeley; and the Canadian Institute for Advanced Research, Canada.
The study authors note that it is well-known that chronic stress can cause reproductive dysfunction; however, it is not known whether stress negatively impacts fertility when it is present just prior to an attempt for pregnancy. Therefore, they conducted a study to assess fertility, sex drive, and stress in a rat model. They studied a single gene and because it encodes for a hormone common in mammals, the findings may apply to humans. They found that stress that resolved four days prior to mating results in persistent and marked reproductive dysfunction, with fewer successful copulation events, fewer pregnancies in those that successfully mated, and increased embryo dissolution.
Chronic stress exposure resulted in elevated expression of the hypothalamic inhibitory peptide, RFamide-related peptide-3 (RFRP3), in regularly cycling females. The hypothalamus is a section of the brain responsible for hormone production. The hormones produced by this brain area control body temperature, thirst, hunger, sleep, circadian rhythm, moods, sex drive, and the release of other hormones in the body. In addition, the hypothalamus controls the pituitary gland and other glands in the body.
The investigators found that genetic silencing of RFRP3 during stress completely resolves stress-induced infertility in female rats, resulting in mating and pregnancy success rates indistinguishable from non-stressed rats. They also showed that chronic stress has long-term effects on pregnancy success, even post-stressor (the time when the stress has resolved, that are mediated by RFRP3. They note that this finding points to RFRP3 as a potential clinically relevant single target for stress-induced infertility.
According to Centers for Disease Control and Prevention (CDC) estimates, 6.7 million, or approximately 11% of, women ages 15 to 44 in the United States struggle with impaired fertility and/or continue a pregnancy to term. The agency also notes that 6% of married women ages 15 to 44 in the U.S. are infertile, according to the CDC.
