Patient information: Barrier methods of birth control

BARRIER BIRTH CONTROL OVERVIEW

Barrier methods of birth control physically block or otherwise prevent sperm from entering the uterus and reaching the egg for fertilization. Barrier contraceptives include the condom, diaphragm, and cervical cap. These methods:

• Have fewer side effects than hormonal contraceptives
• Offer effective protection against certain sexually transmitted diseases (STDs)
• Are available without a prescription (condom and spermicides)

Spermicides (contraceptive creams or gels) are chemical substances that destroy sperm. They are available over the counter and are typically recommended in combination with barrier contraceptives to maximize the contraceptive effect (see 'Spermicide' below.

This topic discusses barrier methods of birth control, including the condom, diaphragm, cervical cap, Lea contraceptive, sponge, and spermicides. A discussion of hormonal and long-term birth control methods are available separately. (See "Patient information: Hormonal methods of birth control" and "Patient information: Long-term methods of birth control".) An overview of all birth control methods is also available. (See "Patient information: Birth control; which method is right for me?".)

CHOOSING A BIRTH CONTROL METHOD

It can be difficult to decide which birth control method is best due to the variety of options available. The best method is one that will be used consistently, is acceptable to the woman and her partner, and which does no cause bothersome side effects. Other factors to consider include:

• Efficacy
• Convenience
• Duration of action
• Reversibility and time to return of fertility
• Effect on uterine bleeding
• Frequency of side effects and adverse events
• Affordability
• Protection against sexually transmitted diseases

No method of contraception is perfect. Each woman must balance the advantages of each method against the disadvantages and decide which method she prefers. A list of questions that are useful for defining a person's preferences are provided in the table (table 1).

EMERGENCY CONTRACEPTION

Emergency contraception (EC, also known as postcoital contraception or the morning-after pill) refers to the use of drugs to prevent pregnancy in women who have had recent unprotected intercourse (including sexual assault), or who have had a failure of another method of contraception (eg, broken condom). Emergency contraception is discussed in detail in a separate topic (see "Patient information: Emergency contraception (morning after pill)".

CONDOMS

Male condom — Male condoms are a thin, flexible sheath or cover that is placed over the penis to prevent semen from entering the partner's body during sexual intercourse. To help ensure optimal effectiveness and protection, people who use condoms must carefully follow instructions for their use.

Condoms are most effective when used with a vaginally-applied spermicide (see 'Spermicide' below; use of the male condom and a vaginal spermicide is as effective as a hormonal method of contraception, and is more effective than a condom alone (table 2A-B). However, spermicidal condoms (those that are packaged with spermicide applied to the condom) are no more effective and expire faster than condoms without spermicide.

When used properly, condoms can also reduce the risk of sexually transmitted infections such as HIV. Studies have found the following:

• There is a decreased risk of gonorrhea, chlamydia, trichomonas, syphilis, HIV, and HPV (human papillomavirus, which can cause genital warts and cervical cancer) in women whose male partner consistently uses condoms. (See "Patient information: Condyloma (genital warts) in women" and "Patient information: Cervical cancer screening" and "Patient information: Testing for HIV".)

• In a study of HIV-negative women whose only risk for infection was a stable relationship with an HIV-infected man, none of the women who consistently used condoms became infected.
• Regular use of latex condoms appears to decrease the risk of HIV infection by about 69 percent.

Oil-based lubricants (eg, suntan oil, petroleum jelly, whipped cream) should not be used with latex condoms because this can cause breakage of the condom. Water-based lubricants are safe (eg, K-Y®, Astroglide®).

Most condoms are made of latex, which can be a problem for people who have an allergy or sensitivity to latex. Polyurethane condoms are available as an alternative to latex. Animal skin condoms (eg, lambskin) are not recommended when there is a risk of HIV infection because they do not effectively prevent transmission of HIV.

Female condom — The female condom is worn by a woman to prevent semen from entering the vagina. It is a sheath made of nitrile and is prelubricated with a silicone-based lubricant. There is a soft, flexible ring at each end (picture 1). The edges of the ring at the closed end of the sheath are squeezed together and then inserted as far as possible into the vagina; upon release, the ring will open to hold the condom in place. The ring at the open end of the sheath remains outside the vulva, resting against the labia. The patient should check to make sure the condom is not twisted.

DIAPHRAGM/CERVICAL CAP

The diaphragm or cervical cap are placed over the cervix before intercourse. Pregnancy is prevented by blocking sperm from entering the uterus and killing sperm with the spermicide (see 'Spermicide' below. Both require fitting by a trained clinician, and the fit should be checked after childbirth and weight loss or gain of more than 10 pounds (4.5 kilograms).

Both devices can decrease the risk of certain sexually transmitted diseases and infections, including gonorrhea, chlamydia, and pelvic inflammatory disease. However, the diaphragm and cervical cap are less effective than condoms in preventing the spread of HIV infection. Diaphragms and cervical caps are not recommended for women at high risk for HIV, who are HIV infected, or who have AIDS as they do not appear to prevent transmission of the virus.

In most studies, the failure rate (number of pregnancies) was higher for users of the diaphragm or cervical cap compared to hormonal methods of birth control (eg, the birth control pill) (table 2A-B).

Diaphragm — The diaphragm is a soft dome-shaped cup made of latex rubber or silicone with a flexible rim. Before intercourse, the hollow of the dome is partially filled with a spermicidal cream or jelly and then the diaphragm is inserted deep into the vagina and positioned so that it fits over the cervix (picture 2). It must be left in place for six to eight hours after sexual intercourse, and then should be removed. If the woman has sex more than once during this time, an additional dose of spermicide should be inserted into the vagina.

Precautions — Most women can use the diaphragm; however; it is not a good method for those who have an allergy/sensitivity to latex, silicone, or spermicides; significant pelvic relaxation (uterine prolapse, cystocele, rectocele, poor vaginal tone); frequent urinary tract infections; HIV infection or are at high risk for acquiring HIV; or have difficulty with the insertion process. Women with a history of toxic shock syndrome should not use a diaphragm.

Cervical cap — The cervical cap is available in latex (the Prentif cap) or silicone rubber (FemCap) in multiple sizes. Similar to the diaphragm, it is partially filled with spermicide and placed over the cervix. It can remain in place for up to 48 hours.

OTHER BARRIER METHODS

There are several other barrier methods, none of which require a prescription. The Lea contraceptive and contraceptive sponge block sperm from entering the uterus and contain a spermicide to kill sperm.

Lea contraceptive — The Lea contraceptive is a pliable, cup-shaped silicone bowl with a one-way valve that allows for the passage of cervical discharge, menses, and air trapped behind the device during insertion. The vaginal walls keep it in place, which helps to provide a better fit. A silicone loop on the bowl eases insertion and removal.

The Lea can be inserted hours before intercourse and is left in place for at least eight and up to 48 hours afterwards, when it is removed and washed. As with the diaphragm, a spermicide is used with the device.

The Lea does not need to be fitted by a clinician (one size fits all) and is available without a prescription from a healthcare provider. Its effectiveness is comparable to that of the diaphragm (table 2A-B). It does not provide reliable protection from sexually transmitted infections.

Sponge — The Today sponge is a 2-inch wide circular disk that is 3/4 of an inch thick and attached to a loop that is used for removal. It contains a spermicide, and is moistened with tap water before insertion deep in the vagina.

The sponge can be left in place and used repeatedly for up to 24 hours. When compared to the diaphragm, the sponge was less effective (table 2A-B).

SPERMICIDE

Spermicides are chemical substances that destroy sperm. They are available in most pharmacies without a prescription. Spermicides are available in a variety of forms including gel, foam, cream, film, suppository, and tablet.

Spermicides may be used alone, but are more effective when used in combination with a condom, diaphragm, or cervical cap. Effectiveness is reduced if the patient does not wait long enough for the spermicide to disperse before having intercourse, if intercourse is delayed for more than one hour after administration, or if a repeat dose is not applied before each additional act of intercourse (table 2A-B).

Local irritation of the vagina is not uncommon with spermicide use, and spermicide-coated condoms are associated with an increased risk of urinary tract infection in the female partner. In the United States, the only spermicide available is nonoxynol-9; use of this spermicide alone is not effective in preventing transmission of sexually transmitted infections, including HIV.

WHERE TO GET MORE INFORMATION

Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two people are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.

This discussion will be updated as needed every four months on our web site (www.uptodate.com/patients). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.

Some of the most pertinent include:

Patient Level Information:
Patient information: A guide to birth control (contraception)
Patient information: Hormonal methods of birth control
Patient information: Long-term methods of birth control
Patient information: Birth control; which method is right for me?
Patient information: Emergency contraception (morning after pill)
Patient information: Condyloma (genital warts) in women
Patient information: Cervical cancer screening
Patient information: Testing for HIV

Professional Level Information:
Approach to intrauterine contraception
Contraception: Overview of issues specific to adolescents
Depot medroxyprogesterone acetate for contraception
Emergency contraception
Female condoms
Fertility awareness-based methods of pregnancy prevention
Hormonal contraception for suppression of menstruation
How to fit and use a diaphragm for contraception
Male condoms
Overview of contraception
Overview of the use of estrogen-progestin contraceptives
Progestin-only pills (minipills) for contraception
Risks and side effects associated with estrogen-progestin contraceptives
Patient information: A guide to birth control (contraception)

A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable.

• National Library of Medicine

      (www.nlm.nih.gov/medlineplus/healthtopics.html)

• National Institute of Child Health and Human Development (NICHD)

      Toll-free: (800) 370-2943
      (www.nichd.nih.gov)

• National Women's Health Resource Center (NWHRC)

      Toll-free: (877) 986-9472
      (www.healthywomen.org)

• Planned Parenthood Federation of America

      Phone: (212) 541-7800
      (www.plannedparenthood.org)

• The Hormone Foundation

       (www.hormone.org)

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