Researchers from the French public health research institute Inserm and Université de Lille have found that polycystic ovarian syndrome (PCOS) begins in the womb when a woman is carrying a female child and affects more than just the ovaries.
PCOS is the most common cause of female infertility, impacting one in ten women of childbearing age. The recent research shows that female offspring who have been exposed in utero to "anti- Müllerian hormone" (AMH), at high levels.
It's not merely a case of male hormones disrupting ovulation and conception in women, however. AMH actually works on the brain, in the hypothalamus, causing neurons there to become overexcited. The hypothalamus is the part of the female brain that regulates reproduction. While it's been believed that levels of AMH only impacted the ovaries, that's not the case according to the team conducting the research.
Patients who present with symptoms of PCOS, which include menstrual difficulty, weight gain, hair loss and infertility can usually be diagnosed quickly, but there is no known cause and no cure. Blood levels of AMH are two to three times higher in women who have PCOS. Some medications can reduce symptoms, and some women can conceive using IVF or other fertility methods, but otherwise not much was known about the disease.
The team in France looked at two factors that are present in pregnant women who have a PCOS diagnosis. The first is an excessive production of androgens (male hormones) and the second is high levels of AMH. In the study, the researchers treated mice with AMH during gestation and found that female pups went to develop symptoms of PCOS.
The in utero exposure to abnormally high levels of AMH in female mice also resulted in increased activity of the GnRH protein-secreting hypothalamic neurons once the mice reached adulthood. When those neurons are stimulated the production of luteinizing hormone (LH) goes up and when that happens levels of androgens are also increased. It's a chain reaction of the AMH exposure, which ups the excitation of the hypothalamic neurons, which then secrete more GnRH. LH production is then increased in the pituitary gland, which impacts the ovaries and causes them to produce more androgens, which then disrupt fertility and cause many of the symptoms women report.
The team, led by Paolo Giacobini of Inserm, came up with a treatment, using an IVF drug, cetrorelix, that normalizes the GnRH, shutting down the cascade of hormonal disruption and infertility. Dr.Giacobini told New Scientist, in an interview, "It could be an attractive strategy to restore ovulation and eventually increase the pregnancy rate in these women." The team plans to begin human trials. Women who have PCOS often struggle with the physical symptoms, as well as the frustration of not being able to conceive a child. With the mechanism of how PCOS works now revealed, many women might find relief and a way to have a child. The video below has more information, check it out.
Sources: Inserm, New Scientist, Newsweek
