Contraception : Barrier Methods

As mentioned, this term covers all methods where contact of the spermatozoa and ovum is blocked by some means or other. It can be achieved by chemical means or by a physical barrier. Chemical agents are vaginal spermicides, such as gel, foam, cream, suppositories, aerosol or foaming tablets. The two products most commonly used in Canada are nonoxynol-9 or benzalkonium chloride. They act in two ways, either by forming a barrier on the cervix or by immobilizing the spermatozoa, which cannot then travel up the woman's genital tract. These products are available in pharmacies, without prescription. It is very important to read the instructions closely. These methods are not sufficiently effective by themselves and are used more as additional protection with other barrier methods. The percentage of failure with the perfect use of this method is 1% to 20% of pregnancies per year.

DIAPHRAGM

A diaphragm is a soft rubber dome (latex or silicone) mounted on a fairly flexible ring which, when introduced into the vagina up to 6 hours before sexual relations, covers the uterine cervix, creating a barrier between the sperm and the cervical canal. The diaphragm must be prescribed by a physician who will have first carried out a thorough gynecological examination to determine whether the woman is a good candidate for this method, and also measure the size of the diaphragm. It must always be used with a spermicide, as described above.

CONTRACEPTIVE SPONGE

A sponge is now available on the market which creates both a chemical and physical barrier. It is easily introduced into the vagina and contains a spermicide that makes it effective.

FEMALE CONDOM

A female condom is now also available from pharmacies. It is relatively effective and provides some protection against sexually transmitted diseases. It is still not very popular in Quebec because it is not well known, but an awareness campaign would no doubt increase its popularity.

MALE CONDOM

This has been around for very many years. The only role that the physician has to play in its use is to recommend it because, when used properly, it is an effective contraceptive and also protects against sexually transmitted diseases.

CERVICAL CAP

The silicone Oves cap is available on the Internet or through some family planning clinics. It works in the same way as a diaphragm and is as effective, but must be used in conjunction with a spermicide. A visit to your physician is necessary to determine which of the 3 types available is suitable for your cervix. The cap may prove less effective in women who have already given birth.

TUBAL LIGATION (LAPAROSCOPY)

If you click on the picture, you will see two video sequences showing a tubal ligation procedure. The first technique is to burn the fallopian tubes using a concentrated electric current; the second is to apply a titanium clip that blocks the tube. These techniques represent the most common methods of female sterilization and are the second most popular method of contraception, after hormone contraception (the Pill).

These excellent pictures are produced by a small camera inserted through the navel, and the two tubes and ovaries can be seen clearly. The ovaries are the small, whitish structures located just underneath the tubes on either side of the uterus. The soft walls at the bottom of the screen form part of the intestine.

TUBAL LIGATION (HYSTEROSCOPY)

This more recent technique, using natural pathways through the vagina and cervix, consists in blocking the tubes by means of a small insert fixed inside the uterus. Varieties of methods are available now or will become available in the near future. This technique has the advantage of not requiring an incision in the stomach and is thus safer and painless. The drawback is that it is not readily available in Quebec because of the cost of the insert and the additional medical training required.

INTRAUTERINE DEVICE (IUD)

An intrauterine device is a very efficient method of contraception, with a continuing high success rate. The reason for this is simple: it has to be inserted and also removed by a physician. This very effective method of contraception can last for up to ten years, depending on the type of device used. Two types of IUD are available in Canada. One is copper-coated and the other releases the hormone progesterone. It also has other advantages besides contraception, as it can help reduce menstrual pain and heavy bleeding.