A B C D E F G H I J K L M N O P R S T U V W

CONTRACEPTION

Background to Contraception

This information sheet gives you an overview of contraceptive methods. More detailed descriptions can also be found, using the related links below. The process of fertilization is as follows. Sperm are deposited at the top of the vagina during intercourse. They then swim up through the womb, along the tube. One sperm fertilizes the egg which has just been released from the ovary (after ovulation). This occurs about 14 days before the next period. The egg then comes down the tube (which is about 10 cm or 4" long), and enters the womb. This journey takes about 3 days. The fertilized egg then buries itself (implants) into the womb lining (endometrium) and develops into the embryo.

Natural contraception

RHYTHM METHOD As ovulation occurs about 14 days before the next period, avoiding intercourse at this time reduces the risk of pregnancy. The sperm is capable of fertilizing for about 4 or 5 days after reaching the tube. The egg is capable of being fertilized for 1 or 2 days after ovulation. A very regular cycle permits one to calculate ovulation accurately. In a 28 day cycle this will be day 14 (day 1 is the first day of the period). Sperm from intercourse on day 10 might survive in the tube until day 14. An egg released on day 14 might survive to be fertilized by intercourse on day 16. So one must assume conception is possible from day 10 to day 17 of a 28 day cycle. An irregular cycle makes the calculation more difficult. If the cycle is always 33 days then assume around day 19 as ovulation (33 minus 14). Some women recognize when they ovulate by keeping a temperature chart and noting body changes. This is helpful but still does not predict ovulation. Advantages: No side-effects. It is acceptable to all religions. Disadvantages: Ovulation can happen earlier or later without warning. Couples find the self-discipline difficult. If practised very conscientiously, the failure rate is less than 1%. Because of the difficulty with timing, ovulation and self-discipline, the failure rate in practice is about 5%. COITUS INTERRUPTUS The male withdraws just before ejaculation. Again there are no medical side-effects but self-discipline is difficult. Sometimes sperm may be produced before ejaculation.

Barrier methods

The condom or sheath is lubricated with a film of jelly which kills sperm. It has the great advantage that it reduces the risk of sexually transmitted diseases such as AIDS. It is often recommended that women using other methods also use a condom for this protection. The disadvantages are the possibility of the condom breaking or coming off. The diaphragm or cap is a device which the woman inserts into the vagina (the diaphragm) or on the cervix (the cap). The correct size must be fitted at a family planning clinic. They must always be used with spermicidal creams, fitted correctly, renewed every year, and not be removed for 6 hours after intercourse. They do protect to some extent from sexually transmitted diseases. The female condom is a rather larger version of the ordinary condom or sheath. The woman places it in the vagina before intercourse. It has a wide neck which is outside the vagina. It is easier to use than the diaphragm or cap . The sponge is a fairly new but very simple method. A small sponge like a tampon, containing a spermicidal chemical, is inserted into the vagina before coitus. It is removed by a small ribbon. Unfortunately it is not very effective. Spermicidal preparations mean medicines for killing sperm. There are creams, pessaries, foams and gels. These should not be used alone but in conjunction with barrier methods or the coil . Advantages: There are no serious medical side-effects. They do protect from infections, especially the condom. Disadvantages: They remove some of the spontaneity from intercourse. They demand some self-control and planning. Because of this they do have a higher failure rate than other methods. They are used successfully by many motivated couples. Occasionally skin irritation occurs.

Intra-uterine contraceptive devices (IUD or coil)

These are small plastic devices inserted into the cavity of the womb. Most types contain a small amount of copper which makes them more effective. The levonorgestrel IUD or Mirena contains a small amount of progesterone hormone that is released slowly into the womb cavity. They do not prevent the egg being fertilized but stop the fertilized egg implanting in the womb. A visit to the family planning clinic or doctor is needed for fitting. The IUD is changed every 5 years. Some can stay in longer if they contain no copper. Advantages: One does not have to think about it or worry about it. It is quite an effective method (about two pregnancies in a hundred women in one year). A progesteone containing coil can reduce the amount of bleeding that occurs during periods. Disadvantages; There may be some discomfort when the coil is fitted and thee is a small risk of it being pushed into or through the wall of the womb. If this occurs it will need to be removed.There may be some spotting or bleeding in between periods during the first few months after a progesterone containing coil is fitted. Other types of coil may make periods heavier and more painful. There is a risk of infection which might cause salpingitis. This is less likely with only one sexual partner. Sometimes the coil gets lost . There is a very fine nylon thread which is attached to the IUD. It is deliberately left just coming through the cervix. When the coil is to be removed, the thread is gently pulled. Either the thread may get stuck inside the womb or it may break. This might mean a general anaesthetic to remove it. Pregnancy with a coil is more likely to miscarry and it is better to remove the coil if possible. There is an increased risk that a pregnancy which occurs while a coil is in places might be in the wrong place (an ectopic pregnancy)

The Pill

The combined pill contains both the female hormones, oestrogen and progesterone. It is usually taken for 21 or 22 days each month. It stops ovulation. There are many different makes and dosages. This is by far the most effective method of reversible contraception available. Like all drugs, especially effective ones, it does have some risks and dangers. Because of this, the pill should not be taken without medical supervision. A rare but important risk is of a clot in a blood vessel (thrombosis). Women who have had this in the past, or with the same problem in their family are at risk. So also are those with a raised blood pressure. Smoking makes it nine times likelier to have a clot. Other side-effects include headaches, putting on weight, acne, loss of sexual interest and breakthrough bleeding. Women on the pill are more prone to thrush. Side-effects can be improved by changing the pill in consultation with the doctor. Advantages: Simple and effective (failure rate less than 0.5 pregnancies in 100 women in 1 year). Disadvantages: Side-effects as above. If forgotten, it should be taken as soon as remembered, or two taken the next day. If two pills are forgotten, a condom should be used for the next 10 days and if this time runs into the week where the pill is not normally taken the next pill packet should be started immediately. Stomach upsets and some antibiotics may reduce the effectiveness. The progesterone only pill ( mini pill ) contains only progesterone and must be taken at the same time every day. It makes the mucus in the cervix thicker and alters the tube and the lining of the womb, making conception less likely. Advantages: Side-effects are much less than the combined pill. The risk of thrombosis is negligible. It can be taken when breast-feeding. Disadvantages: Bleeding may be irregular. The pregnancy rate is about the same as the IUD.

Depot hormone injections

An injection of hormone is given every 10 to 12 weeks. Advantages; contraception is provided for 3 months and one doesn't need to remember to take anything in between injection. It is very effective. It tends to reduce the heaviness of periods. Disadvantages; It may lead to very irregular bleeding and may stop periods for some months

Morning-after contraception

If unprotected intercourse has taken place it may be possible to prevent pregnancy by taking 2 or 3 contraceptive pills on 2 occasions 12 hours apart. This is only effective if the first dose is taken within 72 hours of sex. Special contraceptive pills are need for this type of contraception and the ordinary pill that most women take is not suitable for this use. These pills can be obtained from family planning clinics, emergency departments and pharmacies in some areas. The next period may be early or late but if a women has any heavy bleeding or severe pain she should see her doctor as soon as possible. Following morning after contraception a barrier method of contraception (condom, diaphragms) needs to be used until the next period. If the next period is late or unusually light a pregnancy test should be done as this form of contraception is not 100% effective. An IUD can also be used as a form of contraception after intercourse within 4-5 days of sex occurring. This should be fitted by a doctor experience in family planning.