Birth control pills and the menstrual cycle

Today, birth control pills, or more correctly - hormonal contraceptives are the best means of preventing unwanted pregnancy. But it makes sense to use them in case if a woman is only one sexual partner as sexually transmitted infections by using oral contraceptives can not be prevented.

The history of the birth control pill

Hormonal birth control pills come into our lives for nearly fifty years ago. The first generation of these drugs had many side effects, most of which were unpleasant weight gain and the appearance of a woman masculine traits (body hair and distribution of fat male pattern). Due to the severe side effects of hormonal contraceptives were used in those days is not enough.

Modern hormonal birth control pills do not look like their predecessors: synthetic hormones similar to the natural, reduced the dose several times, without compromising the effectiveness of drugs. Low doses of hormones so reduce side effects of hormonal contraceptives, they have become almost invisible. However, the bona fide manufacturers instructions necessarily indicate the possibility of side effects.

Woman's menstrual cycle

Woman's menstrual cycle begins on the first day of menstruation and ends on the first day of the next menstruation. Just a cycle of 18 to 35 days, but most of them can be 28 or 21. The entire cycle consists of three periods.

First period - maturation of the egg in the ovary. The egg in the ovary is in a special bubble - the follicle. Under the influence of hormones of the pituitary gland (the main endocrine glands in the body, which is in the brain and affects all the other endocrine glands, including the ovaries) and estrogen (ovarian hormones) is oocyte maturation and preparation of the mucous membrane of the uterus for the introduction of a fertilized egg. During this period the leading role played by the pituitary follicle-stimulating hormone (FSH) and estrogen, which are produced in large amounts.

The second period begins after the follicle rupture and release the mature egg from the ovary into the abdominal cavity and fallopian tubes to meet with sperm and fertilization. This period is called ovulation. Ovulation occurs in the middle of the menstrual cycle.

The third period begins right after ovulation and ends with the first day of the next menstruation. During this period, on the site of the ruptured follicle starts a new endocrine gland - the corpus luteum. The corpus luteum secretes the hormone progesterone, which continues to produce mucous membrane of the uterus to the introduction of the fetus and extracts sticky mucus that clogs the cervix, blocking access to the uterus sperm. In addition, progesterone inhibits the maturation of new follicles, which would impede the course of pregnancy. If pregnancy does not occur, then the mucous membrane of the uterus is torn away and menstrual bleeding begins and at the same time the first period of a new menstrual cycle The menstrual cycle - that occurs in different phases? .

During the menstrual cycle, there are times when the pregnancy can not be (the period of absolute sterility - the third period of the menstrual cycle), when pregnancy is most likely not occur (a period of relative sterility - the first half of the first period) and the period when pregnancy is most likely (time ovulation plus two days).

The principle of action of birth control pills

Almost all birth control pills contain a high amount of synthetic analogues of female sex hormones - estrogen and progesterone. Under the influence of a large amount of estrogen inhibits the production of pituitary follicle-stimulating hormone (pituitary hormones are actively released when reducing the amount of estrogen and decrease when they are increasing), and thus inhibited oocyte maturation. Progesterone its part also prevents the maturation of the follicle and stimulates the secretion of viscous mucus, which prevents sperm to penetrate into the uterine cavity.

All birth control pills are usually prescribed for 21 days following 7 days pills are not accepted, which contributes ottrozheniyu mucous membrane of the uterus, and the emergence of menstrual bleeding. Next pills starts exactly seven days, even if the bleeding has ended.

Types of birth control pills

Hormonal contraceptives may contain only one kind of hormones, then they are called one-component. If tablets contain two types of hormones, it is called combined.

Furthermore, the tablets can contain various doses of the hormones according to the day of the menstrual cycle. For more comfortable reception of such tablets are usually painted in different colors. Hormonal contraceptives may be monophasic (same in all dosage tablets) biphasic (two types of tablets) and trehfahnym (three kinds of tablets).

Matches hormonal contraceptive obstetrician-gynecologist of female consultation after a preliminary examination of the woman. The guarantee of a good efficacy is its right neat reception every day at the same hours.

Galina Romanenko

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