The role of the FSH hormone in the female body

The follicle-stimulating hormone (FSH), or follitropin, is produced in the anterior lobe of the pituitary gland and plays a key role in the functioning of the sex glands. In women, it regulates the growth and development of follicles in the ovaries, stimulates the production of estrogens, and promotes ovulation. In men, this hormone acts on the development of seminiferous tubules, testosterone levels, and spermatogenesis.

FSH secretion occurs in a pulsatile manner throughout the day, with intervals of 1 to 4 hours, which constitutes a natural regulatory mechanism of the reproductive system.

The normal range of FSH

The FSH level in the blood varies depending on age and the phase of the menstrual cycle in women.

The normal range of FSH in women of childbearing age (mUI/ml):

• Menstrual phase (day 1-6): 1.3 - 5.9
• Follicular phase (day 3-14): 1.3 - 5.9
• Ovulatory phase (day 13-15): 6.4 - 9.2
• Luteal phase (from day 15 to the beginning of menstruation): 1.1 - 2.8

Before puberty less than 3 mUI/ml

During pre-menopause, FSH levels can vary from 1.7 to 21.5 mUI/ml, and in post-menopause, they reach 25.8 to 134.8 mUI/ml.

Causes of elevated FSH

High FSH levels in women may be due to:

• Primary ovarian insufficiency (pathology or premature ovarian failure);
• Endometriosis;
• Pituitary disorders;
• Hormone-secreting tumors;
• Early puberty.

Factors that may affect test results:

• Smoking;
• Alcohol consumption;
• Use of certain medications (hormonal contraceptives, corticosteroids, antiepileptics);
• A recent MRI study.

Causes of FSH deficiency

A decrease in FSH levels may be a sign of

• Secondary ovarian insufficiency (caused by insufficient production of pituitary hormones);
• Cullman syndrome;
• Sheehan syndrome;
• Hyperprolactinemia (high prolactin levels);
• Anorexia, famine, nutritional deficiencies;
• Polycystic ovary syndrome;
• Hemochromatosis (iron metabolism disorder);
• Tumor formation.

When is it necessary to perform an FSH test?

The FSH analysis is often performed alongside the study of luteinizing hormone (LH) levels. The doctor may prescribe this examination in the following cases

• Interrupted pregnancy;
• Diagnosis of infertility;
• Suspicion of hormonal disorders;
• Menstrual cycle and ovulation disorders;
• Suspicion of pituitary abnormalities.

Where can I have an FSH test done?

At the "Natuvitro" clinic, you can have an FSH analysis and other hormone tests. The clinic offers:

• Advanced diagnostics of hormonal background (including ultrasound, tests for reproductive hormones, tests for the permeability of the fallopian tubes);
• Individualized hormonal therapy;
• In vitro fertilization (IVF) programs;
• IVF with egg donation and double donation.

The specialists at the clinic will help you interpret the study results and choose the appropriate therapy to improve your reproductive health.