By Dr Brigid Monda

The coil is the world’s most widely used and inexpensive long-term reversible method of contraception. In Kenya, the varieties available include the Copper T, which is the commonest, the Nova T and Mirena. Mirena is a hormone-releasing coil whereas Copper T and Nova T are hormone-free, that have copper metal coiled around them. This copper is slowly released into the uterine cavity enhancing the contraceptive effect. Both coils have a ‘string’ attached to them that is made of a single strand of strong, smooth plastic that cannot absorb or ‘wick’ fluid or bacteria from the vagina into the uterine cavity. The string allows for easy removal when the time comes. It also allows a woman or her doctor to judge whether the coil is still in its correct position.

If the string shortens or lengthens, the coil may have moved out of place or if it cannot be located, it may have been expelled or trans-located to another part of the uterus or pelvis.

The Copper T prevents pregnancy for up to 10 years and the Nova T for five years. Both are inserted through the vagina into the uterus in a procedure that takes only minutes. Once inserted, the coil is immediately effective and when removed, its contraceptive effect is immediately reversed. A coil can be inserted at any time during the menstrual cycle because the cervix is open then and a woman is least likely to be pregnant. The menstrual fluid also provides lubrication during the insertion. Another good time to have a coil inserted is mid-cycle during ovulation because the cervix is also open then.

How it works

Scientists are not entirely sure how the coil works but it is thought to slow down or stop the sperm’s movement through the reproductive tract as well as make the ovulated egg travel down the fallopian tube faster. This keeps the egg and sperm from meeting so that the egg is not fertilised. The coil also interferes with implantation of a fertilised egg in the lining of the uterus by making this lining hostile to implantation. The copper adds to the effectiveness of the coil by increasing prostaglandin secretion in the lining of the uterus and thus preventing implantation of a fertilised egg. Prostaglandins are hormone-like chemicals that affect the environment in the cavity of the uterus.

Advantages of IUD

•The most effective reversible long-term method of birth control.

•Very cost-effective because it gives you long-term contraception after just one insertion. Convenient because you do not need to worry about remembering to swallow your pill daily. You only have to remember to check the strings at least once a month to make sure it is still in place.

•Safe and private.

•Can be used by women who cannot use oestrogen-containing birth control pills.

•Can be used by breastfeeding women.

•It can be inserted immediately following the delivery of a baby, immediately after an abortion or immediately after removal of another coil. If a woman has a coil or is fitted one past the age of 40, it can be left in until one year after menopause.

The disadvantages

It does not protect against sexually transmitted infections.

One’s periods may become heavier and longer causing anaemia. Period pains may become worse.

The initial cost of insertion is high because it has to be done by someone trained.

One may have an allergic reaction if allergic to copper. Your partner may feel the strings during intercourse.

The coil may be expelled by the uterus especially in women who have never been pregnant and are likely to be during the first few months after insertion. If the woman does not notice it, she can easily become pregnant. It may also be expelled during a heavy period. In some rare cases, the coil may attach to or become deeply embedded in the uterine wall. It can also work its way through your uterus into your pelvis or abdomen and then has to be taken out through surgery.

There is a slightly higher risk of pelvic inflammatory disease and tubal (ectopic) pregnancy. Fifty to 60 per cent of pregnancies that occur when a woman is using a coil are miscarried if the coil is not removed.

After insertion

You should have checkups after your first period and not longer than three months after insertion to make sure your coil is still in place and then have checkups at least once a year to make sure everything is all right. This can be done when having your annual physical and Pap smear test.

It may also be expelled without your knowing it during a heavy period so you need to check your pads or tampons whenever you change them during your period to see if the coil has fallen out.

Do not use the coil if you:

• Might be pregnant, have a sexually transmitted infection or an untreated vaginal infection.

• Have multiple sexual partners.

• Have had an infected abortion in the past three months.

•Have abnormal vaginal bleeding.

• Have an abnormal Pap smear result or cancer of the uterus or cervix.

• Have a weak immune system due to conditions like leukaemia or AIDS.

• Have anatomical abnormalities of the cervix, uterus or ovaries.

• Have no access to medical care.

• Have a disease of the valves of the heart.

• Have not had any children or have had trouble conceiving in the past.

• Are allergic to copper.