Birth Control Options for Women - Oral Contraception

Highlights	Injected Contraception	Emergency Contraception
Introduction	Intrauterine Devices (IUDs)	Female Sterilization
Oral Contraception	Spermicidal and Barrier Contraception	Resources
Implant Contraception	Natural Family Planning Methods	References

Oral Contraception

Oral contraceptives (OCs) are available only by prescription and come in either a combination of estrogen and progestin or progestin alone. Many brands of each form are available. Although both are equally effective with typical use, the combined pill is more effective with perfect use and most women choose this form.

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Some women, however, experience severe headaches or high blood pressure from the estrogen in the combined pill and must take the progestin-only pill. Not all combined pills or progestin-only pills are alike, and brands differ in the amount of estrogen or progestin they contain. Many OC combined brands now use lower estrogen doses than previous brands and are proving to be safe and effective while providing a better quality of life than earlier OCs.

For all OC users, a check-up at least once a year is essential. It is also important for women to have their blood pressure checked three months after beginning the pill. Former pill users who want to bear children usually regain fertility in three to six months, but they may regain it even sooner.

Hormones Used in Contraceptives

Estrogen (Estradiol)

Estrogen is the major female hormone and is responsible for female characteristics. The estrogen compound used in most oral contraceptives is estradiol and is always used with a progestin.

Effects on Reproduction. When used throughout a menstrual cycle with progesterone, it suppresses the actions of other reproductive hormones (luteinizing hormone, or LH, and follicle stimulating hormone, or FSH) and prevents ovulation. Estrogen also changes the cellular structure of the lining of the uterus (the endometrium) and hinders implantation of a fertilized egg.

Side Effects of Estrogen. During the first two or three months of use of oral contraceptives, side effects from estrogen in the combined pill includes:

Nausea and vomiting. (Can often be controlled by taking the pill during a meal or at bedtime.)
Headaches. (In women with a history of migraines, they may worsen.)
Dizziness.
Breast tenderness and enlargement.

Note: Studies have been conflicting about whether estrogen in oral contraception increases the chances for breast cancer, and if it does, which women are at risk. A reassuring 2002 study supported an earlier major study, with both finding no evidence that OC use increases the risk for breast cancer, even in women who have taken them for 15 years or more or had taken them at young ages. Still, more research is needed to verify these findings, given previous reports of a slightly higher risk.

Progesterone (Progestin)

When used in contraception, progesterone is referred to by one of several names:

Progesterone is the name for the natural hormone,
Progestogen is a synthetic form, and
Progestin is the term for any agent, natural or synthetic, that causes progesterone effects. It is used as the general term in this report.

Progestins may be used alone or with estrogen in oral contraceptives. In addition, certain specific progestins are used in other kinds of contraceptives, such as levonorgestrel in the Norplant system and depo-medroxyprogesterone acetate in the injected Depo-Provera.

Progesterone can prevent pregnancy by itself in a number of ways:

It blocks luteinizing hormone (LH), one of the reproductive hormones important in ovulation.
It maintains a powerful barrier against the entry of sperm into the uterus by keeping the cervical mucus thick and sticky.
It reduces the mobility of the fallopian tubes, thereby inhibiting sperm transport.
It changes the lining of the uterus and makes it more difficult for the fertilized egg to implant.

Progestins used in contraceptives are referred to as:

Second generation (e.g., levonorgestrel, norethisterone).
Third generation (e.g., desogestrel, gestodene, norgestimate, drospirenone). The third generation progestins tend to have fewer male-like side effects. Some studies suggest, however, they may pose a higher risk for blood clots than the older progestins, although the risk is still small. They possibly may have a better effect on cholesterol levels than earlier progestins, but this does not seem to translate into any particular heart benefits.

Side Effects of Progestins. Side effects of progestin occur in both the combination oral contraceptives and any contraceptive that only uses progestin, although they may be less or more severe depending on the form and dosage of the contraceptive. Side effects may include the following:

Changes in uterine bleeding. Such as higher amounts during periods, spotting and bleeding between periods (called break-through bleeding), or absence of periods. It should be noted that some progestin applications can cause heavy bleeding in the first few months. Be sure to check with the physician if any of these occur.
Unexpected flow of breast milk. (Check with the physician if this occurs to be sure other abnormalities are not causing it.)
Abdominal pain or cramps.
Diarrhea.
Fatigue, unusual tiredness, weakness.
Hot flashes.
Decreased sex drive.
Nausea.
Trouble sleeping.
Acne or skin rash. (Not all OCs have this side effect. Low-dose OCs actually improve acne.)
Depression, irritability, or other mood changes. To confuse matters, although OCs with high progestin/low estrogen levels produce worse moods in women without premenstrual syndrome, they may be helpful for women with PMS.
Swelling in the face, ankles, or feet.
Weight gain. (Of note, combination oral contraceptives, which contain progestins, do not cause weight gain.)

Newer formulations of combination pills that use low-dose estrogen and newer progestins may reduce and even avoid many of these side effects, including weight gain. Low-dose progestins used in non-oral contraceptives, such as the LNG-IUS IUD, also may not pose as high a risk for these side effects. If side effects persist or are severe, a woman should always talk to her physician. Many women do not experience these side effects, or for many of those who do, their bodies eventually adjust.