Among the entire spectrum of hormones, the ratio of LH and FSH determines fertility, that is, the ability to become pregnant. From the correct ratio of the level of LH and FSH will depend on the function of the ovary. Therefore, this indicator is such an important aspect in diagnosing the causes of infertility and reproductive system diseases.
Normal parameters of hormones
In the first phase of the menstrual cycle, the FSH level should be greater than the LH level in the blood, and in the second phase vice versa. Actually, therefore, the main periods of the cycle are called the follicular and luteal phases. The index showing the ratio of LH to FSH is very important. Both hormones are produced in the pituitary gland and the target organ they also have in common is the ovary. To determine this indicator, it is necessary to divide the obtained LH level by the FSH index.
The normal ratio of FSH and LH, like other sex hormones, depends on the woman's age and the day of the cycle. It is known that until puberty this ratio will be 1: 1. That is, the girl's body produces the same amount of luteinizing and follicle-stimulating hormones. Then, after a certain time, the level of LH begins to prevail, and the ratio of hormones acquires a value of 1.5: 1. Since the end of puberty and the final setting of the menstrual cycle before the onset of the climacteric period, the FSH index stays stable less than the LH level one and a half to two times.
Change in the ratio of hormones
The level of hormones is quite variable and depends on many factors. Therefore, in order for the result of the analysis to be as reliable as possible before taking blood for analysis, certain rules must be observed:
- at least an hour before the manipulation should not smoke;
- analysis is given on an empty stomach;
- one day before the expected date of analysis, you can not drink alcohol-containing beverages, and avoid physical exertion and emotional stress.
Usually, these hormones are determined from 3 to 8 days of the menstrual cycle. And in this period the correct ratio of hormones FSH and LH is from 1.5 to 2. But at the beginning of the follicular phase (until the third day of the cycle), the ratio of LH FSH will be less than 1, which is necessary for the normal maturation of the follicle.
The ratio of LH and FSH equal to 1 is acceptable in childhood. The ratio of the level of LH and FSH 2.5 and more is a sign of the following diseases:
pathology of the ovaries ( polycystic ovary syndrome or ovarian malnutrition); tumors of the pituitary gland.
In addition, it should be added that such a high content of LH leads to excessive stimulation of ovarian tissue. As a result, more androgens can be synthesized, the processes of oocyte maturation are broken and as a result - ovulation does not occur.