FSH Hormone and its Influence on Fertility and Menstrual Cycle

The FSH hormone, also known as follicle-stimulating hormone, plays a major role in the female cycle . Men also have FSH, but in this article, we'll focus on this hormone in women: what is FSH and what does it do?

The FSH hormone is produced in the pituitary gland, a small organ located at the base of the brain. Starting at puberty, girls begin producing more FSH. This coincides with sexual maturation and a changing body.

In women, the FSH hormone causes the follicles, which contain the eggs, to grow in the ovaries. Only one follicle fully develops per cycle.

Follicle development occurs during the first part of the menstrual cycle, from the first day of menstruation until ovulation. This takes an average of 14 days and is called the follicular phase.

FSH cannot, in fact, be viewed separately from the entire female hormonal cycle. Hormones are essentially the communication channel between the brain and the reproductive organs.

The phases of the cycle vary, and therefore the hormone levels also vary. Hormones present during the female hormonal cycle are: FSH, LH, estrogen, and progesterone.

In short, the hormone cycle goes like this:

• Egg development - Multiple follicles develop in both ovaries. This occurs under the influence of the hormone FSH. These follicles release estrogen, which makes the cervix more suitable for sperm.
• Complete development of a single egg - Only one follicle fully develops per cycle. When this happens, significantly more estrogen is released.
• The ovulation - The pituitary gland recognizes the estrogen and releases the hormone LH. The follicle ruptures, and ovulation occurs, with the egg moving from the follicle and ovary into the fallopian tube.
• Journey to the Womb - The egg travels through the fallopian tube to the uterus. The empty follicle produces the hormone progesterone. Progesterone and estrogen prepare the uterine lining for a potential pregnancy and inhibit the hormones that cause more eggs to develop.
• Menstruation - If fertilization has not occurred, estrogen levels drop, you menstruate, and the cycle starts again.

An elevated FSH level can be detected through symptoms and subsequent blood tests by a doctor. This doesn't always have a clearly identifiable cause. For example, the ovaries may simply not be functioning properly.

Three common identifiable causes of elevated FSH are menopause, PCOS, and Turner syndrome. These will be explained below.

The main cause of an elevated FSH level is menopause. This is, of course, a normal occurrence for women as they get older. Unfortunately, menopause can also occur in young women, meaning you become progressively less fertile. This is called premature menopause when it occurs before the age of forty.

Symptoms of premature menopause are[ 1 ]:

1. Menstruation is absent for more than four months
2. Hot flashes
3. Bad sleep
4. Mood swings
5. Dry skin and vagina
6. Reduced fertility

Do you recognize these symptoms? Then see a doctor. They can determine whether you're in menopause or if there's another cause for your symptoms.

Research has shown that women with PCOS have higher FSH levels[ 2 ]. PCOS stands for Polycystic Ovarian Syndrome. This is a condition in which fluid-filled sacs develop in the ovary or ovaries. It is often associated with fewer menstrual periods and reduced fertility.

Symptoms of PCOS include[ 3] :

• Irregular or absent menstruation
• Gaining weight
• Reduced fertility
• Excessive hair
• Acne

Turner syndrome is a congenital birth defect that affects 1 in 2,500 females. If you have this syndrome, you are missing one or two female X chromosomes. It is often only discovered during puberty, when menstruation and growth of the female body do not occur properly.

Low FSH levels are much less common. When they do occur, the cause is often due to hormone production in the hypothalamus or pituitary gland.

Symptoms of too little FSH include:

• Irregular or absent menstruation
• Reduced fertility
• Hot flashes
• Dry vagina
• Less desire for sex
• Osteoporosis

Hypopituitarism is the production of too few hormones by the pituitary gland[ 4 ]. Possible causes include a (benign) tumor, a congenital abnormality, brain trauma, an inflammation or an injury to the pituitary gland.

A reduced FSH hormone level can also be caused by a decreased function of the hypothalamus. This is called hypothalamic amenorrhea. Causes of this can include:

• Lots of sports
• Low body weight
• Anorexia Nervosa or Orthorexia Nervosa
• Stress

The pituitary gland is then not properly stimulated by the hypothalamus and releases little FSH. The menstrual cycle then malfunctions, and fertility decreases.

Both high and low FSH levels are associated with lower fertility and other health issues. As you've read, unfortunately, there's not always anything you can do about this, or you'll need to see a doctor.

If you have low FSH levels due to hypothalamic amenorrhea, there are sometimes tips that can help, such as making lifestyle changes. A healthy lifestyle is always good for your mind, body, and hormone balance.