Follicle Stimulating Hormone (FSH) is a hormone that, when drawn at the beginning of your menstrual cycle (usually days 2, 3, or 4), can provide information about reproductive potential. If your fertility doctor has told you that you have high baseline levels of FSH (follicle stimulating hormone), you’re probably wondering what that means. The level of FSH in your blood typically correlates with the number of follicles (the tiny sacs in your ovaries that contain the eggs) you have left. As the number of follicles drops, the level of FSH increases.
The most common reason for very high FSH levels is that you are beginning menopause. Because you have fewer remaining follicles, your body produces less of a hormone called Inhibin B, which is responsible for keeping FSH levels down. This means that your pituitary gland continues to produce more and more FSH, as your body tries harder to grow and mature the remaining follicles.
Conditions Related to High FSH
Does high FSH definitely mean that you are entering menopause? If you are under 35, high FSH levels are not considered normal, and may indicate one of several things.
It could be premature menopause — also known as premature ovarian failure or ovarian insufficiency. If this is the case, you will have other signs of menopause as well, like missing your period and low levels of estrogen. These symptoms may be more severe than in women in natural menopause, and is considered atypical as it begins much earlier. About one percent of women have this condition.
High FSH levels could also indicate poor ovarian reserve — also known as impaired ovarian reserve, premature ovarian aging, premature ovarian insufficiency, or declining ovarian reserve. In this condition, you either have relatively few eggs left in the ovaries, or impaired development or recruitment of the eggs. Recent research suggests that this condition may be a precursor to premature ovarian failure.
There are also some congenital or genetic conditions that can result in high levels of FSH, such as Turner Syndrome or Congenital Adrenal Hyperplasia. However, these are usually identified early in life, and are unlikely to be responsible for newly diagnosed high FSH levels.
Also, extremely rarely, high FSH levels could be the result of a pituitary tumor.
The bottom line is that high levels of FSH are, unfortunately, an indicator of infertility or decreased fertility.
Dr. Alan Copperman is a board-certified reproductive endocrinologist and infertility specialist with a long history of success in treating infertility and applying fertility preservation technologies. He serves as Medical Director of Progyny, the nation’s leading fertility benefits provider, and co-founded and serves as Medical Director of RMA of New York, one of the largest and most prestigious IVF centers in the country. Dr. Copperman is also the Vice Chairman and Director of Infertility for the Icahn School of Medicine at Mount Sinai, and Chief Medical Officer of Sema4, a health information company. Dr. Copperman has been named to New York magazine’s list of Best Doctors 17 years in a row. He has been recognized by his peers and patient advocacy organizations for his commitment to patient-focused and data-driven care. He has published more than 100 original manuscripts and book chapters on reproductive medicine and has co-authored over 300 scientific abstracts on infertility, in vitro fertilization, egg freezing, ovum donation, and reproductive genetics.