Birth control definition and facts
- Terminology that is used to describe birth control methods includes:
- No matter what terminology is used, sexually active people can choose from a number of methods to reduce the possibility of pregnancy. Nevertheless, no method of birth control available today offers perfect protection against sexually transmitted infections (sexually transmitted diseases, or STDs), except abstinence.
- In simple terms, all methods of birth control are based on either preventing a man's sperm from reaching and entering a woman's egg (fertilization) or preventing the fertilized egg from implanting in the woman's uterus (her womb) and starting to grow.
- New methods of birth control are constantly being developed. This ongoing evolution of contraceptive technology allows a couple the flexibility to change their choice of birth control based on their personal circumstances at the time.
- Unfortunately, no birth control method, except abstinence, is considered to be 100% effective, and this continues to be seemingly insurmountable problem in the developments of new contraceptive options.
What are barrier methods of birth control (contraception)?
Barrier methods of contraception work by creating a physical barrier between sperm and egg cells so that fertilization cannot occur. The most common forms of barrier contraception are:
Spermicides, a form of chemical contraceptive that work by killing sperm, are often combined with barrier methods of contraception for greater effectiveness.
Barrier methods of contraception generally do not have the side effects of hormonal contraceptives, and some forms of barrier contraception (contraceptive sponges and condoms) may be obtained without a prescription and easily purchased over the counter at pharmacies.
The only medical contraindication to the use of barrier contraception is latex allergy (when using latex condoms). However, with the exception of male and female condoms that can provide some protection against infection with sexually-transmitted diseases (STDs), most methods of barrier contraception are not effective in preventing STDs.
During sexual intercourse, hundreds of millions of sperm are normally released into a woman's vagina. The large majority of these sperm die. They die because of the vagina's unfriendly environment, which is acidic, and because the mucus in the cervix above the vagina acts as a selective filter for the sperm. Only about 1% of all the sperm released in an ejaculation successfully pass through the woman's vagina and cervix to reach the uterus (the womb). However, it only takes one sperm to fertilize the ovum (the egg) and to achieve conception.
Spermicides are a type of contraceptive agent that work by killing sperm.
Spermicides need to be placed in a woman's vagina prior to intercourse if they are to prevent viable sperm from reaching her uterus. Spermicides come in a wide variety of forms, including jellies, creams, foams, films, and suppositories. The active ingredient in essentially all spermicides is Nonoxynol-9. This is a detergent-like chemical that kills sperm (i.e. spermicidal).
Once placed inside the vagina, the spermicide melts into a liquid that coats the vagina in order to provide a chemical barrier between the sperm and the cervix. Spermicidal foams are more effective than creams or jellies. Not only is it possible to achieve a better distribution with foam, but foam adheres better to the vaginal walls and cervix.
Suppositories are solid or semi-solid inserts which must be inserted in the vagina 15 minutes before intercourse in order to bind with vaginal moisture and liquefy.
Vaginal contraceptive film needs to be in place in the vagina about 5 minutes prior to sexual intercourse in order to liquefy and become effective.
Spermicides resemble other methods of birth control in that they must be used properly in order to prevent pregnancy. Each type of spermicide has a unique method of use. For example, spermicidal creams, gels, and foams need to be deposited high up in the vagina near the cervix. Spermicidal suppositories must be unwrapped and inserted in the vagina. Squares of spermicidal film should be inserted into the vagina with the user's finger. It is important to follow the package's exact instructions.
A spermicide should be placed in the vagina prior to the man's penis entering the vagina. It is a common mistake for a couple to wait too long before using the spermicide.
There are two basic concerns with any given spermicide. 1) How long the spermicide stays in the desired place; and 2) how long the spermicide is active in killing sperm. Therefore, the timing of spermicide use must take into account both of these factors.
In general, spermicides tend to be effective soon after their application. They can be inserted 15 minutes or more before intercourse. However, if there is a significant delay before intercourse (for example an hour), more spermicide must be added.
A fresh application of spermicide must also be used for each act of intercourse.
Douching should be avoided for at least 8 hours after the last intercourse.
The effectiveness of spermicides in preventing pregnancy varies from 70 to 90%. This depends on the amount of spermicide and how it is used, the timing of use prior to intercourse, and how well the instructions on the package are followed.
Spermicides should not be used as protection for the woman or man against sexually transmitted infections (sexually transmitted diseases, or STDs). While spermicides may be partially protective against certain organisms that cause sexually transmitted infections, (e.g. Chlamydia and gonorrhea), they also do not protect against the human Immunodeficiency virus (HIV) infection.
The main objection voiced concerning spermicides is that they are "messy." A small percent (2% to 4%) of people may have an adverse reaction to Nonoxynol-9, which is experienced as an irritation or a burning sensation within the vagina or on the external genitalia.
Spermicides have some positive features. They are relatively inexpensive and they are available over-the- counter (OTC) without a prescription.
Note that some lubricating jellies available over-the-counter do not contain spermicide and are not meant to be used as a form of birth control. It is important to check the information on the package to be sure that the product contains spermicide or that the word "contraceptive" appears on the label.
Male condoms are far more common than female condoms. A male condom is a thin sheath that is worn over the man's penis during sexual intercourse. The condom collects sperm so that it is not released into the vagina. Condoms are known as rubbers, sheaths, prophylactics, and many other names.
Condoms are made from a variety of materials including latex, rubber, plastic polyurethane, and animal tissue. They are also available in a variety of sizes, colors, styles, and thicknesses. They may be dry, lubricated, or treated with a spermicide. Although convenient, a wallet is not the best place to store condoms. Condoms last longer when they are stored under less moist conditions. In general, condoms have a shelf life of about five years if stored unopened in a cool, dry place.
A condom must be the correct size and fit the man's erect penis properly. There should be 1/2 inch (about 1.25 cm) at the tip of the condom to provide a space for the sperm-filled semen to collect. Some condoms have this feature built in.
Prior to any contact between the penis and the vagina, the condom is unrolled over the erect penis, ensuring the condom is not turned backwards or inside out. Some condoms come pre-lubricated. If additional lubrication is desired, a water-based product should be used. Spermicides may be used as lubricants with condoms and may thus increase the efficacy of the condom. Oil-based products such as Vaseline, vaginal creams, or mineral oil, may damage the condom and should never be used.
There is an obvious problem of lack of barrier protection if the condom breaks, slips, or comes off the penis. Condoms are quality controlled in the U.S. by the Food and Drug Administration (FDA) for manufacturing defects that could result in breakage. Condom failure can also be caused by the user and/or his partner. For example, long fingernails or jewelry can tear condoms.
Immediately after ejaculation, the condom should be removed from the vagina. It should be held firmly in place at the base of his penis, as it is withdrawn from the vagina. Care must be taken not to spill any of the ejaculate from the condom.
Each condom must be discarded after a single use. A new condom must be used for the next act of intercourse. Male condoms are not reusable.
Condoms can be purchased over-the-counter (OTC) without a prescription. Most of those on the market are made of latex. The estimated effectiveness of the latex condom is 87% to 90% or 10 to 13 pregnancies/100 women per year of sexual activity.
About 1% to 3% of people are allergic to latex. In such cases, they may be able to use condoms made of polyurethane, a type of plastic, can often be used. However, polyurethane condoms may break more easily than latex condoms and they do not protect against sexually transmitted infections (sexually transmitted diseases, or STDs).
Latex condoms afford the maximum protection against sexually transmitted infections including HIV (human immunodeficiency virus) and herpes virus. According to the U.S. Centers for Disease Control and Prevention (CDC), consistent and correct usage of latex condoms:
- is highly effective in preventing sexual transmission of HIV, the virus that causes AIDS.
- reduces the risk for many STDs that are transmitted by genital fluids (STDs such as Chlamydia, gonorrhea, and trichomoniasis).
- reduces the risk for genital ulcer diseases, such as genital herpes, syphilis, and chancroid, only when the infected area or site of potential exposure is protected.
- may reduce the risk for genital human papillomavirus (HPV) infection and HPV-associated diseases (for example, genital warts and cervical cancer).
Animal membrane condoms, made from the intestines of sheep, when used with contraceptive foam, can be effective in preventing pregnancy, but they may not provide adequate protection against all sexually transmitted infections. This is because the pores in the animal tissue permit small organisms such as viruses to pass through.
The most frequent complaint lodged regarding condoms is that their usage decreases sexual pleasure for the male. This is an unfortunate attitude because male condoms are an effective, acceptable, inexpensive, and safe method of birth control.
The female condom is not well known in the United States. It is essentially a cylindrical vaginal pouch made of soft polyurethane (a type of plastic) with a ring at either end. One end of the pouch is open. The other end is closed. A woman inserts the closed end high up in her vagina over her cervix. The open end remains on the outside of her vagina. The vagina is now lined with the condom. When she has intercourse, the man inserts his penis into the open end of the woman's condom. Once intercourse is over and the man withdraws his penis, the condom containing the semen can now be removed and discarded.
The female condom can be put in up to 8 hours before intercourse. A significant amount of practice may be necessary before a woman can properly insert and position a female condom. The sides of the internal ring can be folded together and inserted into the vagina much like a diaphragm is inserted. The female condom is thinner than the male condom and is resistant to degradation by oil-based lubricants.
A female condom should never be used when the man is also wearing a condom. The two condoms can stick together and tear, resulting in a total loss of protection.
The female condom (Reality) was approved by the U.S. Food and Drug Administration (FDA) in 1993. The Reality Condom is made of polyurethane, but other types of female condoms are available in other areas of the world. Its estimated effectiveness is 85% (15 pregnancies/100 women per year) as compared to 87% to 90% for the male condom.
Problems associated with the female condom include irritation and allergic reactions to the polyurethane. Other concerns are that the female condom is cumbersome, difficult to insert, may not remain in place, and is unattractive. It may also produce unpleasant noises if there is not enough lubrication. For this reason, most female condoms are now generously pre-lubricated with silicone and packets of additional lubricant are included. The lubricant does not contain spermicide.
The female condom (Reality) can be purchased over-the counter (OTC) without a prescription, but it may cost more than a male condom. Package instructions currently advise single use but studies are underway to determine if the female condom can be safely washed and reused up to five times.
The main disadvantage of the female condom is that it is not as effective as its male latex counterpart.
The main disadvantage of the female condom is that it is not as effective as the male latex condom in preventing pregnancy.
The contraceptive sponge is a doughnut-shaped ring of polyurethane foam and is impregnated with the spermicide Nonoxynol-9. This chemical confers most of the contraceptive efficacy of this product.
Before intercourse, a woman inserts the sponge high into the vagina in the manner similar to the insertion of a tampon. The spermicidal sponge should then act as a barrier in order to prevent sperm from reaching the cervix. Once in place, the sponge provides protection for up to 24 hours without the need for additional spermicide.
The sponge must remain in the vagina for at least 6 hours following intercourse in order to provide optimum contraception. However, the same sponge should never remain in the vagina for more than a total of 30 hours because of the risk of toxic shock syndrome. (Toxic shock syndrome is an uncommon and potentially very serious illness that is caused by a type of bacteria. This illness occurs when certain types of products, such as tampons,are left in place for excessive periods of time. Package inserts for these products are careful to specify how long they may be safely kept in place. Each sponge is discarded after a single use.
The sponge is generally an effective birth control. Some users of the contraceptive sponge may experience irritation and allergic reactions. The sponge can also be difficult to remove from the vagina. Removal has been made easier by the addition of a woven polyester loop which can be more easily grasped with the fingers.
The estimated contraceptive efficacy of the sponge is estimated to be between 64% and 82%. The spermicide may provide some protection against Chlamydia and gonorrhea, but otherwise, the degree of this protection is unknown.
The diaphragm is a soft, flexible, dome-shaped latex cup which is inserted into the vagina prior to intercourse. The rim of the cup contains a coil spring of metal which serves to hold it in place. The diaphragm blocks access to the cervix so that sperm cannot pass from the vagina into the uterus. The diaphragm must be covered on both sides and especially around its rim with spermicidal jelly, cream, or foam in order to form a tight seal with the vaginal walls.
A woman should insert the diaphragm into her vagina no more than 4 hours prior to intercourse. Following coitus, she should check the diaphragm should be checked to ensure that it was not mechanically dislodged. The diaphragm must be left in place for at least 6-8 hours following intercourse, at which time it should be removed. Additional spermicidal jelly or foam must be inserted into the vagina each act of intercourse.
Since diaphragms are only available with a prescription, a woman must see a health care practitioner to have a diaphragm properly fitted (they come in a range of sizes), and to learn proper insertion techniques. There are no known long-term health risks associated with using the diaphragm and spermicide method of birth control. Some women may find spermicides to be irritating, but changing brands of spermicides may help. There is also an increased risk of urinary tract infections with diaphragm use. One possible reason is that the diaphragm puts increased pressure on the urethra or the spermicide may contribute to irritation leading to infection. (The cervical cap is not associated with increases in urinary tract infections.)
The diaphragm may be appealing to women because it offers a safe temporary (not permanent) birth control that is under her control.
When the diaphragm and spermicide are used correctly, they are thought to have over an 82% success rate (18 pregnancies/100 women per year). To ensure protection, it is important to check the diaphragm after every use for rips or holes after each usage. This is best accomplished by filling the diaphragm with water and then holding it up to the light to observe for leakage. Also, the fit of the diaphragm should be checked annually, following pregnancy, and after significant weight loss.
Using a diaphragm does not confer protection against sexually transmitted infections, although the spermicide does give partial protection against gonorrhea and Chlamydia. It can, however, be used with condoms in order to confer some protection against sexually transmitted diseases (STDs).
The cervical cap is a small (1-1/2 inches or about 3 cm.), thimble-shaped dome made of latex or silicone rubber (it is much smaller than a diaphragm) which fits directly over the cervix. The cervical cap is used in conjunction with a spermicide. One small application of spermicide is placed inside the cap at the time of insertion. The cap plus spermicide prevent sperm from going through the cervix and entering the uterus.
The cervical cap is gently inserted into the vagina and positioned over her cervix. It can be inserted as long as 8 hours prior to intercourse, and can be allowed to remain in place for up to 48 hours. Unlike the diaphragm, fresh spermicidal jelly or foam does not need to be added with each act of intercourse as long as the cervical cap is correctly positioned over the cervix.
As with the diaphragm, a cervical cap requires a prescription. A woman must see a health care practitioner to determine the correct size and to ensure that she understands the proper insertion and removal techniques.
There are no known significant health risks associated with using the cervical cap and spermicide. The cervical cap can be difficult to insert, but it may be helpful for women who are unable to use a diaphragm because of poor muscle tone. Women who suffer from recurring urinary tract infections related to diaphragm usage may also want to elect to try the cervical cap.
It is important to remember that using a cervical cap does not protect from sexually transmitted infections, although spermicides may give some protection against Chlamydia and gonorrhea.
When the cervical cap and spermicide are used properly, they are more than 80% effective in achieving reliable contraception.
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REFERENCE: Cacey, FE, MD, et al. Contraception. Medscape. Updated: May 16, 2018.
CDC. Condom Fact Sheet in Brief.