In a whole world hormonal contraception is the most popular and effective method, its efficiency makes at the correct application 99%.
 In order to understand the mechanism of action of hormonal contraceptives, we will appeal to the sources of physiology of womanish organism. All changes what is going on in the organism of woman are cyclic, I.e. repeat oneself through the certain amount of time. By a cycle it is accepted to name the period of time from the first day of appearance of the menstrual bleeding to the offensive following, on the average a cycle makes 28 days, but can grow short to 21 day or lengthen to 35 that also is physiology. In the middle of menstrual cycle (approximately on 14 day at a 28-daily cycle) there is ovulation that output of mature ovule in the cavity of small pelvis and if she at this juncture “meets” with a spermatozoon, pregnancy comes. All this difficult process is regulated by womanish sexual hormones – estrogen and progesteron.
Principle of action of hormonal contraceptives is based on suppression of ovulation. In addition, gestagens, entering in the complement of hormonal contraceptives, viscidity of mucus being in the channel of neck of uterus is multiplied, the same hinder to passing of spermatozoa in the cavity of uterus.
It is necessary to mark that hormonal contraceptives differentiate on composition and divide into a few groups:
1. Oral contraceptives only with progestin for permanent application (“mini-pills”).
2. Preparations-depots only with progestin for intramuscular introduction.
3. Combined preparations-depots for intramuscular introduction.
4. Preparations only with progestin for hypodermic introduction.
5. Preparations only with progestin for urgent, “fire” contraception.
How you see, a list is large enough, therefore we will dwell on every point individually.
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