Oral Contraceptives
Oral contraceptives, also called the birth control pill, supply the body with the synthetic versions of the hormones progesterone and sometimes estrogen. Progesterone (also known as progestin) and estrogen are two types of female sex hormones. These hormones attach to the cell walls and trick the body into believing that it is pregnant. Both prevent the reproductive hormones from triggering ovulation, however, progesterone also thickens the cervical mucus so that sperm cannot move freely. Progesterone also prevents the tissue (known as the endometrium) that lines the wall of the uterus from thickening as it would during a normal cycle. With a thin lining, an egg is unable to implant into the uterine wall and therefore, pregnancy cannot occur.
Depo-Provera
The Depo-Provera injection is given every three months and works just like an oral contraceptive. According to the University of California, this medication contains the synthetic version of progesterone and works by preventing ovulation and thickening the mucus that blocks the cervical opening (known as the cervical os).
IUDs
An Intrauterine Device, also known as an IUD, is a small T-shaped plastic device that is inserted into the uterus by a physician. The IUD works by blocking the path to the fallopian tubes and irritating the uterus enough so that implantation could not occur. The Mirena IUD, which contains hormones similar to the birth control pill, also prevents ovulation and the thickening of the uterine lining.
Condoms, Spermicide and Feminine Caps
Condoms work by capturing the semen inside a latex sheath that is worn over an erect penis. When the man ejaculates, the semen does not enter the women, as it is collected at the tip of the condom.
Spermicide is a chemical that is toxic to sperm. The spermicide is inserted into the vagina before intercourse and will kill any sperm that enters. It will also block the cervix.
A feminine cap works by covering the cervix inside of a woman and blocking any sperm from entering the uterus. The cap is placed before sexual intercourse and can be removed afterward.
