Birth control pills are not only the most modern but also the most effective method of contraception. If they are taken strictly as prescribed by gynecologist and without missing doses, these pills provide 98-100% effectiveness in preventing unwanted pregnancy. Detailed information about various types of birth control pills can be found on http://www.drugs-med.com
So how do these pills work? Actually, they prevent pregnancy using several mechanisms but primarily by preventing ovulation – if the ovaries release no egg, there is nothing to be fertilized by the male semen and thus the woman can’t become pregnant. Birth control pills usually contain various synthetic forms of two female hormones: progestin and estrogen. They stabilize natural levels of hormones in the female body, and prevent estrogen from peaking in the middle of the cycle which results in the pituitary gland not releasing other hormones required for the ovaries to release a mature egg.
There are two types of birth control pills:
- Combination pills (such as Yasmin) that contain both types of hormones – progestin and estrogen.
- Mini-pills that contain only one hormone – progestin. Progestin-only pills are prescribed to those women who cannot take estrogen for some reasons.
Synthetic progestin in such pills works to:
- Not let the pituitary gland produce luteinizing hormone in order to inhibit the release of an egg.
- Partially restrict the ability of the sperm to fertilize an egg.
- Change the quality of the cervical mucus and thicken it to impede the movement of the sperm and prevent it from getting into the uterus.
- Make the lining of the uterus (endometrium) thinner so that an egg that may have been released and fertilized could not attach to the wall of the uterus and thus preventing pregnancy.
Whereas, synthetic estrogen works to:
- Prevent the pituitary gland from synthesizing luteinizing hormone and follicle stimulating hormone in order to stop ovulation.
- Support the endometrium to prevent a sudden bleeding in the middle of the cycle.
This wonderful protective mechanism works only when these pills are taken exactly as administered, any violation of the birth control regimen, even missing only 1 day, can weaken the contraceptive effect and increase the chances of becoming pregnant.