Contraception for overweight women poses some challenges. Some methods that work well in average weight women have been shown to be less effective in obese women, but not all contraceptive methods are affected by weight. Determining which form of birth control is right for you begins with learning about the different methods and how they may be affected by weight.
Contraceptives Impacted by Weight
Birth control methods that change hormone levels in the body may not be as effective on women who are within the obese or morbidly obese range as they are with women who are not overweight.
According to a 2010 journal article in Seminars in Reproductive Medicine, 28 (2), there is a risk for failure of oral contraceptives in obese women. More research is needed to determine how big this risk actually as, and at what weight these risks become a concern. Women should consult with their health care provider to determine if oral contraceptives are the right choice for them.
Considerations for obese women include:
- Excess weight is associated with an increased metabolism. This could lead to faster clearance of oral contraceptives from the body and inability to reach an effective level of concentration of hormones to prevent pregnancy.
- Larger circulating blood volume in obese women leads to diluted concentration of contraceptive medicines and decreased efficacy.
- Increasing dosage of oral contraceptives to counteract a higher metabolism and larger circulating blood volume could lead to dangerous side effects, including an increased risk of thrombosis.
Birth Control Patch
The birth control patch is also a hormone-based contraceptive and may be ineffective in women with significant weight problems.
Contraceptives Not Affected by Weight
According to WomensHealth.gov, the diaphragm is a small disk made of latex. A physician fits the device specifically to the woman's body. The efficacy of the diaphragm is not affected by weight, as it is specifically fitted to the individual.
The disk is reusable and it is used in combination with a spermicidal agent for full effectiveness. This device serves as a barrier that prevents sperm from reaching the egg and should be left in for at least six hours after intercourse to ensure effectiveness. The device is 85 percent effective in preventing pregnancy.
Male and female condoms can be effective in preventing pregnancies as barrier methods. The effectiveness of condoms is not affected by weight of the individual. These non-prescription methods are available in many stores, making them convenient options.
According to WebMD, the proper use of male condoms and spermicide together offer 97% effective prevention of pregnancy. Female condoms, when used properly, are 75% effective at preventing pregnancy. Many choose to use these devices in conjunction with spermicidal agents.
An intrauterine device (IUD) is placed in the uterus by a physician. The device prevents the sperm from reaching the egg and prevents the egg from attaching to the uterine wall. According to the VeryWell Health, IUDs are safe for use in obese women.
There are two types of IUDs for women to consider:
- The copper IUD places small amounts of copper inside the uterus, making it a hostile environment for sperm. Once placed, it is effective for up to 12 years.
- The hormone IUD is effective for up to 5 years. This device contains progestin which changes the mucosal lining of the cervix and prevents sperm from entering the uterus.
WebMD states that IUDs are more than 99% effective in preventing pregnancy.
Some overweight women can benefit from exploring natural methods of contraception. The approaches typically require regular monitoring and testing and they are usually less effective than man-made forms of birth control, but their efficacy is not impacted by weight.
Permanent Birth Control
Permanent birth control is another option to consider if you are certain you want no more children. These procedures are non-reversible and offer permanent protection from pregnancy. Obesity does not change the effectiveness of these procedures. Procedures include:
- Tubal sterilization
- Essure, which is a non-surgical option
Vasectomy of male partner
Work With Your Doctor
You should work closely with your doctor to determine which birth control method is right for you. Having an understanding of the different types of birth control and how weight may or may not change the efficacy of the method will help you to choose the right method for your lifestyle.