Birth Control Hormonal Methods

"The pill" was introduced in the United States in 1962 and signaled a new era for women and their ability to control their fertility.  
 
The pill remains the leading birth control method used by women younger than 30 years, according to the Centers for Disease Control and Prevention. Longer-acting implants, injections, rings, and patches that use hormones to prevent the ovaries from releasing eggs or to create a poor environment for sperm to fertilize an egg are also available.    
 
The ultimate decision of which birth control method to use is best made by each individual woman in consultation with her health care provider. Each method has risks, benefits, advantages, and disadvantages.

Birth control pills, also known as oral contraceptives, have been marketed in the United States since 1962. Over the past 40 years, the type of estrogen and progestin (hormones) used in the pills has changed and the amounts of those hormones has been lowered. 
 
Birth control pills today are designed to improve safety and reduce side effects. Lower doses of estrogen are associated with a decrease in side effects, such as weight gain, breast tenderness, and nausea. 

Birth control pills are taken by mouth and swallowed with a liquid. In late 2003, the US Food and Drug Administration (FDA) approved a spearmint-flavored chewable birth control pill called Ovcon 35. These pills contain the same hormones, progestin and estrogen, that are present in standard birth control pills. Packages contain 21 active pills and 7 inactive pills to be taken throughout one menstrual cycle. You may chew the pills or swallow them whole. If you chew the pill, you should drink 8 ounces of water afterward to make sure the full dose reaches your stomach. The chewable version has similar side effects to other birth control pills, such as an increased risk for blood clots, heart attacks, and strokes.

Over 30 different combinations of birth control pills are available in the United States. Most of the combinations of these pills have 21 hormonally active pills followed by 7 pills containing no hormones. A woman begins taking a pill on the first day of her period or the first Sunday after her period has begun. By taking a pill a day, a woman can usually take pills consistently throughout her cycle.   

• Monophasic pills: These have a constant dose of both estrogen and progestin in each of the hormonally active pills.
  
  
• Phasic pills: These combinations can alter either or both hormonal components to try to mimic the natural menstrual cycle.   

If a woman misses 1 or 2 pills, she should take 1 tablet as soon as she remembers. She then takes 1 tablet twice daily until each of the missed pills has been accounted for. Women who have missed more than 2 consecutive pills should be advised to use a backup method of birth control at the same time, finishing up the packet of pills until her next period.
 
The pills prevent ovulation (release of an egg) and thus prevent pregnancy. 
 

• How effective: Pregnancy rates range from 0.1% with perfect use to 5% with typical use. 
  
  
• Advantages: Birth control pills are used to treat irregular menstrual periods. Women can manipulate the cycle to avoid a period during certain events, such as vacations or weekends by extending the number of intake days of hormonally active pills or by skipping the nonactive pill week. Birth control pills prevent certain conditions, such as benign breast disease, pelvic inflammatory disease (PID), and functional cysts. Functional cysts are reduced by the suppression of stimulation of the ovaries. Ectopic pregnancies are prevented by the cessation of ovulation. Birth control pills have been known to prevent certain ovarian and endometrial cancers.  
  
  
• Disadvantages: Problems in taking birth control pills include nausea, breast tenderness, breakthrough bleeding, no periods, headaches, depression, anxiety, and lower sexual desire. Birth control pills do not provide protection from sexually transmitted diseases (STDs). Taking the pills daily and consistently (same time every day) is important. If a woman stops taking birth control pills, she may need a few months to get her normal ovulatory cycle back. After 6 months, her health care provider may need to be examine her.
  
  
• Additional risks: Some women may be at risk for blood clots (venous thrombosis). At particular risk are heavy smokers (especially those older than 35 years), women with high or abnormal blood lipids (cholesterol levels), and women with severe diabetes, high blood pressure, and obesity.

The association of birth control pill use and breast cancer in young women has been controversial, although more recent studies show that birth control pills will not increase one’s risk to develop breast cancer. 

The relationship between birth control pill use and cervical cancer is also quite controversial. Important risk factors include early sexual intercourse and exposure to the human papillomavirus. The thinking now is that if birth control pills increase the risk of cervical cancer, the risk is small and related to sexual behavior. Thus, women who use birth control pills should have a periodic Pap test.

The FDA has approved a birth control pill that you take for 12 weeks (84 days) followed by 1 week (7 days) of an inactive pill. A menstrual period occurs during that week, every 3 months. The pills (known as Seasonale) contain the hormones already approved for other, 28-day birth control pills. 

Instead of having a menstrual period once a month, a woman taking Seasonale would have a period every 3 months. Although Seasonale users have fewer scheduled menstrual cycles, the data from clinical trials show that many women, especially in the first few cycles of use, had more unplanned bleeding and spotting between the expected menstrual periods than women taking a conventional 28-day cycle birth control pill.

Seasonale is effective for prevention of pregnancy when used as directed.

• The risks of using Seasonale are similar to the risks of using other birth control pills and include an increased risk of blood clots, heart attack, and stroke.
  
  
• The labeling also carries the warning that cigarette smoking increases the risk of serious heart-related side effects from the use of combination estrogen- and progestin-containing contraceptives.

Since Seasonale users can expect to have fewer periods, the label also advises women to consider the possibility that they may be pregnant if they miss any scheduled periods.

Progestin-only pills, also known as the mini-pill, are not used widely in the United States. Fewer than 1% of users of oral contraceptives use them as their only method of birth control. Those who use them include women who are breastfeeding and women who cannot take estrogen.

New in the United States is a transdermal patch (worn on the skin) that releases estrogen and progesterone directly into the skin (brand name, Ortho Evra). Each patch contains a 1-week supply of hormones. It releases a low daily dose equivalent to the lowest-dose oral contraceptive. The birth control patch is easy for women to use because it works for a week, and women do not have to remember a pill every day. A new patch is applied every week for 3 weeks, and a patch is not worn during the fourth week when you have a menstrual period. It is available by prescription.
 
Side effects for the birth control patch are similar to those experienced by women using oral contraceptives. However, the patch may cause skin irritation where it is placed (near the bikini line, on the buttocks or upper body). Sometimes, it may come off and not be noticed, for example, in the shower, and it will become less efficient. In August 2002, the FDA listed a failure rate for the patch of 1 pregnancy per 100 women per year, similar to that of other combination methods. It may be less effective for women who weigh more than 198 pounds. The patch does not protect against STDs.

The vaginal ring (NuvaRing) is a new form of birth control. The actual design of a vaginal ring as birth control was first developed in the 1970s. The vaginal rings can deliver progesterone or progesterone/estrogen combinations. The hormones are released slowly and absorbed directly by the reproductive organs. Preliminary studies show that, like birth control pills, they safely prevent pregnancy with few side effects. These would be used in the same schedule as birth control pills, with 3 weeks of ring usage and 1 week without to produce a menstrual period. If the ring comes out on its own and remains out for more than 3 hours, you must use another form of birth control until the ring has been back in place for at least 7 days. It is available by prescription. The vaginal ring does not prevent STDs.

The FDA approved the contraceptive use of implants (levonorgestrel, brand name Norplant) in 1990. In 2003, the manufacturer decided not to continue marketing the Norplant System to health care professionals. The company has chosen to focus on developing other birth control options. Current users with medical questions may call the Norplant System Information Line at (800) 364-9809.

This method consists of inserting 6 silicone rubber rods (about the size of matchsticks) under a woman’s skin in her upper arm. They can be seen and felt under the skin.
 
The implant releases medication throughout the period of use and begins to work within the first 24 hours. Protection may be provided for 5 years. The hormone stops ovulation.   

• How effective: Implants are as effective as surgical sterilization. Overall, pregnancy rates increase from 0.2% in the first year to 1.1% by the fifth year. 
  
  
• Advantages: Implants last a long time. A woman can become fertile again once the implants are removed (again, surgically).  
  
  
• Disadvantages: A minor surgical procedure is necessary to place and remove them. Difficulty in removal is a disadvantage. Menstrual irregularities are common along with other side effects, including weight gain, headaches, mood changes, growth of facial hair, flow of milk from nipples, and acne. This method does not protect against STDs.
  
  
• Additional risks: Implants are often used for women who have just had a child and are breastfeeding, for those who have trouble remembering to take birth control pills or use other birth control methods, and for women who should not get pregnant because of a medical condition. Implants are not recommended for heavy smokers or women with a history of ectopic pregnancy, diabetes, high cholesterol, severe acne, high blood pressure, heart disease, migraine, or depression.

Although the Norplant system is no longer available, a new single-rod system (Implanon) using a form of the progestin desogestrel and providing 2-3 years of contraception is currently available in Europe and may soon be available in the United States.

Injections

An injection of a synthetic hormone medroxyprogesterone acetate (DMPA, Depo-Provera) can be given every 3 months to stop ovulation. The injection is given at a doctor’s office. After injection, the medication is active within 24 hours and lasts for 3 months. It prevents the ovaries from releasing eggs.
 

• How effective: DMPA is an extremely effective contraceptive option. Most other medications or a woman’s weight do not change its effectiveness. Within the first year of use, the failure rate is 0.3%. 
  
  
• Advantages: DMPA does not produce the serious side effects that estrogen does, such as blood clotting. It lowers the risk for certain endometrial and ovarian cancers. Irregular periods may become regular.
  
  
• Disadvantages: Some women may not have a period within the first year. Irregular bleeding can be treated by giving the next dose earlier or by temporarily adding a low-dose estrogen. Because DMPA lasts in the body for several months in women who have used it on a long-term basis, it can delay the return to fertility. About 70% of former users desiring pregnancy conceive within 12 months, and 90% of former users conceive within 24 months. Other side effects, such as weight gain, depression, and menstrual irregularities, may continue for as long as 1 year after the last injection. Recent studies suggest a possible link between DMPA and bone density loss. Results are conflicting and limited. This method does not protect against STDs.

Combination injection

One of the newest developments in contraception is a combined monthly injection (medroxyprogesterone acetate [progesterone] and estradiol cypionate [estrogen], brand name Lunelle). It recently received FDA approval in the United States. The injections stop ovulation like birth control pills do. They thicken cervical mucus to prevent sperm from traveling up the fallopian tubes to fertilize an egg and thin the uterine lining to prevent an egg from implanting. 

Women who want to become pregnant may stop using Lunelle at any time. Some women have an immediate return to fertility. Others may have to wait 60-90 days for normal menstrual cycles.

• How effective: When used correctly, Lunelle is 99.8% effective. One-year failure rates of less than 1% have been reported in clinical trials. In one US study of 782 women, no pregnancies were reported after 1 year of use. 
  
  
• Advantages: A woman can regain fertility after 2-3 months after the last injection. Few users of Lunelle experience problem periods or no periods. Lunelle can protect the uterus from cancer and endometriosis and reduce the likelihood of ovarian cysts and tumors. 
  
  
• Disadvantages: Disadvantages include irregular blood spotting, weight gain, headache, mild depression or mood changes, and possible decrease in sexual desire. You are required to see your health care provider each month for the injections and may have to fill the prescription at the pharmacy and then take the medication with you to the provider for the injection. Injections are given every 28-30 days and no later than 33 days after the last injection. Timing is determined by the number of days, not your menstrual period. Some women may not have a period but should have the injection on schedule. In contrast to other hormonal contraceptive methods, due to its novelty, associated cancer risk is not known. More extensive worldwide use and additional studies may demonstrate the risk, if any, on cancer of the reproductive tract. Some women may experience changes in vision, especially for contact lens wearers. There is a higher risk of gallbladder disease. Any woman with a history of blood clots, stroke, heart disease, breast cancer, unexplained vaginal bleeding, and high blood pressure should avoid Lunelle. Women older than 35 years who smoke should not have these injections. This method does not protect against STDs.

Unfortunately, the combination injectable contraceptive is no longer available in the United States, although it is popular in Central America and South America and other parts of the world.

|Web Links|

Family Health International, Reproductive Health, Combined Injectable Contraceptives FAQ 
 
Food and Drug Administration, What Kind of Birth Control is Best for You?  
 
Food and Drug Administration, Birth Control Guide 
 
National Cancer Institute, Cancer Facts, Oral Contraceptives and Cancer Risk  
 
Nemours Foundation, Birth Control Pill  
 
Nemours Foundation, Depo-Provera  
 
Planned Parenthood, Facts About Birth Control 

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Author: Omnia M Samra, MD, Clinical Instructor, Department of Obstetrics and Gynecology, Medical College of Pennsylvania/Hahnemann University.

Editors: Bryan D Cowan, MD, Director, Division of Reproductive Endocrinology, Professor, Department of Obstetrics and Gynecology, University of Mississippi College of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, ; Lee P Shulman, MD, Professor of Obstetrics and Gynecology, Head, Section of Reproductive Genetics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.