Various birth control modalities work through different mechanisms of action to prevent pregnancy. Here are the mechanisms of action for commonly used birth control methods:
1. Hormonal Methods:
a. Combination Oral Contraceptives (COCs): These contain synthetic versions of the hormones estrogen and progestin. They primarily work by suppressing ovulation, preventing the release of eggs from the ovaries.
b. Progestin-Only Pills (Mini Pills): These contain only progestin and work primarily by thickening cervical mucus, making it difficult for sperm to enter the uterus, and thinning the uterine lining, making it less receptive to implantation.
c. Contraceptive Patch: Similar to COCs, the patch releases estrogen and progestin through the skin and works by inhibiting ovulation and altering cervical mucus.
d. Contraceptive Implant: A small, flexible rod inserted under the skin of the upper arm that releases progestin to prevent ovulation and thicken cervical mucus.
e. Hormonal Intrauterine Device (IUD): Releases progestin locally into the uterus, which thickens cervical mucus, inhibits sperm movement, and reduces the ability of the uterine lining to support implantation.
2. Barrier Methods:
a. Condoms: Create a physical barrier that prevents sperm from entering the vagina.
b. Diaphragm/Cervical Cap: Blocks sperm from entering the cervix.
c. Spermicides: Chemical agents that immobilize or kill sperm.
3. Intrauterine Devices (IUDs):
a. Copper IUD: Creates a toxic environment for sperm, impairing their ability to reach and fertilize an egg. It may also prevent implantation.
b. Hormonal IUD: Releases progestin, which thickens cervical mucus, inhibits sperm movement, and reduces the ability of the uterine lining to support implantation.
4. Emergency Contraception:
a. Copper IUD: When inserted within a few days after unprotected sex, it can prevent fertilization or implantation.
b. Emergency Contraceptive Pills (Morning-After Pill): High doses of progestin or a combination of estrogen and progestin can inhibit ovulation, disrupt fertilization, or prevent implantation.
5. Sterilization:
a. Tubal Ligation (for women): Surgically closing or blocking the fallopian tubes, preventing sperm from reaching the egg.
b. Vasectomy (for men): Surgically cutting or blocking the vas deferens, preventing sperm from entering the ejaculate.
It is important to note that these mechanisms may vary in effectiveness and do not protect against sexually transmitted infections (STIs). Consulting with a healthcare provider can help determine the most suitable birth control method based on individual needs and health considerations.