The Coil

Dr. Blasio Omuga explains how the coil works and why it sometimes fails.

A coil, also known as an Intrauterine Contraceptive Device (IUD), is a tiny plastic or metal (usually copper) loop that is placed in the uterus, it is inserted into the uterus through the cervical canal, which connects the uterus to the vagina. A wide variety of shapes and sizes are available. Coils are inexpensive and provide long-term prevention of pregnancy.

How many types of coils are there?

There are three types of coils.
o Simple copper and plastic devices—most common and have been around for the longest time,
o Beaded coils—relatively new and consist of a thread of beads. They cause less of bleeding and face less risk of expulsion.
o Hormone impregnated coils-which release progestogens (hormones) to prevent pregnancy. They tend to cause a reduction in the thickness of the lining of the womb and cause lighter periods. They are sometimes used to treat heavy periods.

Can I get pregnant while using a coil?
Coils, just like all other methods of birth control, are not 100% effective. Their effectiveness ranges from 95% to over 99%. This depends on the specific device used, the number of pregnancies the woman has had before and her age. On average, 0.4 to 2.8 per cent of women using the coil may get may get pregnant after 12 months of use.

How does the coil work?
The coil works in several ways. It may interfere with implantation of the fertilised egg onto the wall of the uterus. Some types of coils release small amounts of synthetic progesterone (a hormone) into the uterus to prevent conception. Once inserted the coil remains in place in place for 3 to 8 years depending on the type. Research shows that the main effect is to prevent fertilisation in the first place. It hinders passage of sperms to the fallopian tubes, reducing opportunity for fertilisation.

What causes pregnancy while using a coil?
Pregnancy can occur while a woman is using the coil due to the following reasons:

Spontaneous expulsion of the coil. This may happen in the first few months after insertion of the coil; it especially happens during menstruation. The user should therefore examine herself routinely after menses to be sure that the tail of the coil is in place. If the tail is not there, the coil could have been expelled. The tail of the coil could have been retracted into the uterine cavity or the coil could have perforated the uterus and become lodged in the intra-abdominal cavity.

The chance of coil expulsion depends on the stiffness, size and shape of the uterus. The coil also exits as a result of spontaneous contractions of the uterus or improper insertion. After expulsion, a similar coil may be reinserted.

Expiry of the coil. The device must not be used for longer than the duration recommended by the manufacturer, if the period of use is extended, it renders the coil ineffective, especially if the coil is hormone impregnated or made of metal.

Pregnancy before insertion. To avoid the possibility of one being pregnant before the coil is inserted, coils are usually inserted during menses. However some women may have spotting in early pregnancy coinciding with the time they usually have periods. They may confuse this with normal periods and thus insert the coil at this time, if this occurs, there is a 50% chance of the pregnancy being retained and another 50% chance of abortion.

Alternatively, coils may be inserted immediately after delivery or during the pueperium (the period following childbirth, normally within 6 weeks after delivery) before resumption of sexual activity.

What next after a pregnancy with a coil?
If pregnancy occurs with a coil and one wishes to continue with the pregnancy, the device may be removed by gentleman’s traction on the plastic tail of the coil. If this does not effect prompt and easy removal, it is best to leave the device in place. However, removing the coil increases the chances of the pregnancy succeeding. If the coil remains in place, it significantly increases the risk of miscarriage. The incidence of abortions with the device in place is approximately 50%. This is in contrast to the incidence of abortions occurring in pregnancies where a coil is not involved—about 12%.

Can the coil cause congenital defects?
There is no increased incidence of congenital malformations in pregnancies conceived with a coil in place.

What are the side effects of using the coil?
The copper-based devices may cause increased menstrual flow which may, in rare cases, lead to anaemia. In such situations, a hormone-based coil may be used as a substitute.

Metal allergies (for those using copper-based coils) can occasionally cause itching around the vulva (external opening of the vagina), particularly during periods. If this is confirmed, the user may switch to a non-metallic device.

Coils can cause cramping in the lower abdomen. If these cramps are severe, the user should be evaluated to rule out other possible medical conditions. She would then be counselled before deciding whether to continue using the coil.

The coil may cause an increase in normal secretions from the cervix. It can lead to infection of the upper genital tract (uterus, cervix, tubes). If a user has a per-existing sexually transmitted infection (STI), this can spread faster in presence of the IUD. The coil should not be used by women who have a high risk of acquiring STIs.

END: PG8/6-7