Unintended pregnancies remain high in the United States, at an estimated 50% of all pregnancies.
Unintended pregnancies remain high in the United States,1 at an estimated 50% of all pregnancies.1 Of these, about half occur in women who report using birth control at the time of conception.1 Contraception is defined as the deliberate prevention of conception or impregnation by various drugs, techniques, and devices; it is birth control.2
Unintended pregnancies occur in higher proportions in adolescent and young women, in women with lower levels of education and income, and in women who are ethnic/racial minorities.1 These pregnancies increase the risk for poor mother/child outcomes and result in billions of dollars in direct health care costs each year.1
Several factors should be taken into account when a woman is weighing her options for birth control, such as her overall health, age, weight, frequency of sexual activity, number of sexual partners, family history of certain diseases, and desire to have children in the future.3 In general, there are 5 types of birth control: barrier methods, hormonal methods, emergency contraception, intrauterine devices, and sterilization.3 Not every type of birth control is appropriate for every situation.
Barrier methods, which are removable, are designed to prevent sperm from entering the uterus.3 Some also provide protection from sexually transmitted diseases (STDs).4 This method of birth control is not as effective as others: approximately 18% to 28% of women will become pregnant despite using it.4 Following are brief descriptions of several common barrier methods:
Male condoms are single-use thin sheaths that are placed over the penis to collect sperm. Most are made of latex or polyurethane that also protect against STDs. Those made of lambskin do not provide protection from STDs.3
Female condoms are thin, flexible, single-use pouches, part of which is inserted vaginally and traps sperm before it can get to the uterus. Female condoms also provide protection from STDs.3
Diaphragms are reusable shallow, flexible latex or rubber cups. They are inserted vaginally after they are coated with spermicide, and they work to block sperm from entering the uterus. Diaphragms need to remain in place for 6 to 8 hours after intercourse, but should be removed within 24 hours after intercourse. This method of birth control must be sized by a health care provider and should be replaced every year or two. The Silcs diaphragm, which does not need to be sized, is currently in clinical trials for approval in the United States.3
The cervical cap is a small, rigid silicone cup similar to the diaphragm. It is used in the same manner, but is smaller in size, can be left in place for up to 48 hours, and can last up to 2 years.3
Contraceptive sponges are soft, disposable foam sponges filled with spermicide. They are inserted into the vagina prior to intercourse and should be left in place for at least 6 hours after intercourse; remove them within 30 hours.3
Spermicides destroy sperm and are available in foam, jelly, cream, suppository, and film formulations. They need to be inserted high up into the vagina no more than 30 minutes prior to intercourse and left there for 6 to 8 hours.3
Containing small amounts of manmade hormones, these methods work to prevent pregnancy through a combination of factors. These hormones typically stop the body from ovulating, as well as change the mucus around the cervix, making it difficult for sperm to penetrate. They also change the lining of the uterus, reducing the likelihood of a fertilized egg implanting.5 Hormonal contraceptives are available as an oral tablet, a transdermal patch, and a vaginal ring.
Combined oral contraceptives (COCs) contain estrogen and progestogen. However, there are also progestogen-only, or progestin-only, pills (POP), also known as the mini-pill.6 Advantages of POPs include use during lactation and in some women that are not candidates for COCs.6 Disadvantages include irregular periods and increased risk of breast cancer, and they must be taken at the same time every day.6 Advantages of COCs include their efficacy and few adverse effects (AEs). They ease painful periods and reduce the risk of ovarian and uterine cancers, and the AEs go away quickly after discontinuation.6 Disadvantages include a risk of blood clots (especially in smokers) and an increased risk of breast cancer. COCs should not be used in patients with uncontrolled high blood pressure, certain types of migraines, or a personal or family history of blood clots.6
The contraceptive patch has the same hormones as COCs and works in the same ways, but is easier to use. Some disadvantages include that the skin can become irritated and the patch may peel off6 and may not be effective for patients weighing over 198 pounds.7
Vaginal rings are thin flexible rings, approximately 2 inches in diameter, that are inserted into the vagina and left in place for 3 weeks. They have the same hormones and effects as COCs and have the same advantages and disadvantages as the patch. Body weight does not affect their efficacy.3,6
Injectable birth control, which involves a shot of depo medroxyprogesterone acetate into the arm or buttocks once every 3 months3 and has a similar profile to POPs,6 works by preventing ovulation. The most worrisome AE is a temporary loss of bone density, particularly in adolescents.3
Emergency contraception refers to hormone pills taken as a single dose or 2 doses 12 hours apart as soon as possible after semen exposure, usually within 72 or 120 hours, depending on what you choose to use.8 These pills can inhibit ovulation by at least 5 days, allowing for semen to become inactive.3 They also interfere with sperm function and cause a thickening of mucus around the cervix.3 Pregnancy may occur if these pills are taken after ovulation or semen exposure continues during the same cycle.3
Intrauterine devices (IUDs) are T-shaped and inserted into the uterus by a health care provider. They can remain in place and function for years at a time.3
Hormonal IUDs release levonorgestrel into the uterus, which may prevent ovulation. This progestin hormone also thickens cervical mucus, inhibiting sperm from reaching the egg, and thins the uterine lining, preventing implantation of a fertilized egg.3 Hormonal IUDs can be used for up to 5 years before they must be replaced.3
Copper IUDs release small amounts of copper into the uterus. The resulting inflammatory response generally prevents sperm from reaching the egg. Should an egg become fertilized, however, the presence of the IUD prevents it from implanting in the uterus.3 Copper IUDs can remain in place for up to 12 years.3
Sterilization permanently prevents a man from releasing sperm or a woman from becoming pregnant. These procedures can only be performed by a health care provider.
A sterilization implant is a method used to block fallopian tubes. During the procedure, a soft, flexible, spring-like device is inserted into each tube. The device will irritate the tubes, causing scar tissue to form, which will eventually block the tubes, thereby disallowing ovulation.9
Tubal ligation is a surgical procedure for female sterilization during which a physician will cut, tie, or seal the fallopian tubes. This results in failure of the egg to enter the uterus. This procedure can sometimes be reversed, but doing so requires major surgery and does not always work.10
A vasectomy is a surgery for male sterilization in which the vas deferens (the tubes that carry sperm from the testicles to the urethra) are cut, closed, or blocked so that sperm cannot leave the testes.3 It can take as long as 3 months to be fully effective. Once a vasectomy is complete, it is very difficult to reverse, and the procedure may not be successful.11
Dr. Kenny earned her doctoral degree from the University of Colorado Health Sciences Center. She has more than 20 years of experience as a community pharmacist and works as a clinical medical writer based out of Colorado Springs, Colorado. Dr. Kenny is also the Colorado Education Director for the Rocky Mountain Chapter of the American Medical Writers Association and a regular contributor to Pharmacy Times.