Learn about Birth Control

Contraception, also known as birth control, uses a variety of devices, drugs, sexual practices, or surgical procedures to prevent conception or pregnancy.

Oral Contraceptive Pills

Oral contraceptive pills* (OCPs, also known as birth control pills [BCPs]) trick the pituitary gland into producing less of the two hormones needed for ovulation. When there is less follicle stimulating hormone (FSH) and less luteinizing hormone (LH), there is a decreased chance of ovulation and thus a decreased chance of becoming pregnant. Simply put, oral contraceptives decrease, but do not eliminate ovulation.

There are two other effects of Oral Contraceptives:

  • They thin the lining of the uterus and decrease its thickness thus decreasing blood supply
  • There is weak evidence that OCPs thicken cervical mucus making it difficult for sperm to travel up the cervix 1

Implants and Intrauterine Devices

Implants and intrauterine devices* that are hormone-based work very similar to oral birth control, i.e. reducing ovulation, thinning the lining of the uterus, and thickening cervical mucus. Non-hormonal intrauterine devices interfere with sperm motility and viability by inhibiting egg transportation or damaging the egg itself, and helping to prevent implantation

While the above choices decrease the chance of ovulation, a woman may still ovulate. If she does and fertilization takes place, implantation does not typically occur. 2  3  4

Barrier Methods

Contraception that prevents fertilization from occurring includes barrier methods such as the sponge, diaphragm, cervical caps and shields, and male and female condoms. With these types of birth control, the egg and sperm ideally never meet and fertilization never occurs; where there is no fertilization there is no concern about implantation.

Behavior-based Methods

Behavior-based methods involve abstinence, Natural Family Planning (NFP), and Fertility Awareness-Based (FA) Methods. Both NFP and FA work by identifying a woman’s fertile days each month and avoiding sex on those days.

Permanent Contraception

Permanent methods of birth control involve tubal ligation for women and vasectomy for men.


Other forms of birth control include “the Shot”*, which works like other hormone-containing methods; spermicides, which are inserted into the vagina prior to sex and destroy sperm; and patches, which contain high levels of estrogen and work as any other hormone-containing method. [1.“Contraception,” Julie Quinn, MD; CME Resource/Net CE; 2013]

  1. Preventing Fertilization.
    Fertilization takes place when a man’s sperm and a women’s egg join. Some birth control forms a physical barrier to block this union of the sperm and the egg. Male and female condoms and the diaphragm are in this category.
  2. Making the Uterus Hostile to Implantation.*
    Some contraceptives prevent the fetus from implanting in the woman’s uterus after fertilization
    by creating a hostile environment. Intrauterine Devices (IUDs) and chemical methods are in this category.
  3. Altering Body Chemistry.*
    Typically referred to as “hormonal” contraceptives, synthetic steroids like the pill mimic hormones to prevent pregnancy by changing a woman’s body chemistry, which has three impacts:
  • Prevents ovulation, the release of the egg each menstrual cycle.
  • Produces less and thicker mucus, making it more difficult for sperm to enter the uterus.
  • Thins the lining of the uterus, making it more difficult for a fertilized egg to implant itself in the mother’s uterus.

Oral contraceptives birth control, Depo-Provera injections, the patch, and the implant are contraceptives in the chemical category. Chemical methods of birth control provide no protection against STDs and can actually make your reproductive tract more vulnerable to infection, increasing your risk of contracting an STD.

*Note: Chemical birth control methods provide no protection against STDs and can actually make your reproductive tract more vulnerable to infection, increasing your risk of contracting an STD.


  1. LifeIssues.net. (n.d.). How Do the Pill and Other Contraceptives Work?. Retrieved from http://www.lifeissues.net/writers/kah/kah_03howpillworks1.html
  2. IMPLANON. (n.d.). IMPLANON® (etonogestrel implant) 68 mg – How it works. Retrieved from http://www.implanon-usa.com/en/consumer/about-it/how-it-works/index.xhtml
  3. Paragard.Retrieved from http://paragard.com/Pdf/ParaGard_full_brochure.pdf
  4. Mirena® | How Does It Work. (n.d.). Retrieved from http://www.mirena-us.com/about-mirena/how-mirena-works.php