FSH (follicle-stimulating hormone)

A hormone that stimulates the growth of follicles, a structural component of the ovary. FSH prepares the ovum for maturation. In men, the hormone stimulates the growth of the seminal tubules in the testicles and their function of producing sperm.

The level of the hormone in the blood changes throughout the menstrual cycle, reaching the maximum level of FSH leads to ovulation, which is the release of the egg from the ovary. Thus, the first phase of the menstrual cycle is under the influence of FSH as the follicle increases and produces the female hormone called estradiol. Then the concentration of FSH and LH increases sharply, which leads to the rupture of the follicle and the release of the egg for a potential “meeting” with sperm. After this comes the luteal phase, and FSH stimulates the production of progesterone and its concentration gradually decreases. Thus, the content of the hormone at the beginning of the menstrual cycle is less than in the middle, but more than at the end.

Production of FSH has one peculiarity as it is produced in “portions” with an interval of 1 - 4h. At the moment of hormone release, its concentration for 15-20 minutes exceeds the average value by 1.5-2 times. There are contradictory data on the normal ratio of LH / FSH, in this regard, it is impossible to operate on this indicator with a hundred percent probability. According to the Russian National Guidelines for Gynecology (2009) LH / FSH < 1.5 is a sign of congenital dysfunction of the adrenal cortex, >2.5 means polycystic ovary syndrome.

Preparation: Attention! The analysis should be taken on certain days of the menstrual cycle, namely on day 6-7 of the menstrual cycle. For the most effective diagnostics, check the day of the test with your doctor.