The contraceptive coil comes in two different types: copper-based intrauterine devices (IUD) and hormonal intrauterine devices (sometimes known as IUS – intrauterine system). Both are essentially made of plastic, then either "coated" with copper or hormones.
Both methods of IUD contraception are inserted into the uterus to provide long-term and highly effective protection against a pregnancy (above 99% effectiveness).
This protection lasts for 5-10 years.
They do not protect against sexually transmitted infections.
This IUD is a small T-shaped device that releases copper ions that kill sperm. The coil itself works by stopping sperm from going to the ovaries and by stopping a fertilized egg from implanting in the uterus.
There are threads attached to it that lie in your vagina so that it is easy to remove and easy for you to check it is still in place.
This makes it a viable solution for emergency contraception if inserted within 5 days after unprotected sex.
The copper coil works for about 10 years with a few check-ups needed every once in a while to make sure that everything is okay. This contraception is about 98-99% effective over a period of 5 years.
The obvious advantage is that once it is in place, you don't need to think about contraception every day.
Except a risk of heavier periods, copper IUD contraception doesn't cause many side effects because it doesn't rely on hormones to prevent pregnancy.
Your doctor needs to implant the IUD. You'll need to go back to your doctor for a check-up one month after that to see if the coil is still well-placed. Follow-ups after this are also necessary.
In terms of side effects, some women have experienced heavier and more painful periods with the copper-based contraceptive coil. This can be a problem if you are already prone to heavy and painful periods, if that's the case, this type of contraception might not be right for you.
Other side effects are uncommon but include:
Your doctor will check for signs of infection in the 3-4 weeks after the contraceptive coil is inserted.
Another (rare) risk is that the IUD comes out or slips out of its place – which mostly happens during the first 3 months. If that happens you should see your doctor as soon as possible. You can also try to check the threads that come with it to see if it is in place.
For your own safety, you should never try to put the IUD back in place yourself, always leave it to a healthcare professional.
Women who tend to expel the contraceptive coil usually have never been pregnant, are below age 20, have heavy periods or had the coil inserted right after childbirth.
The physical appearance of the hormonal coil is fairly similar to that of copper-based ones. It is the same T-shaped plastic device, except that it is “coated” with hormones in this case.
The effect of these hormones is, rather than killing sperm, to make it very difficult for sperm to reach the ovaries by modifying the texture of the uterus. This also makes a fertilized egg less likely to successfully implant in the womb.
Moreover, the hormones prevent the ovaries from releasing an egg, and although this effect is only partial, it is combined with the protection of the coil.
It has the same threads as the copper-based coil making it easy to remove and to check its position.
Hormonal intrauterine contraception is just as effective as a copper-based one in protecting against pregnancy. Even though it “only” lasts about five years, it also makes periods much lighter and less painful after about 3-6 months.
This method can also be a treatment for heavy periods and endometriosis. It also reduces the risk of pelvic inflammatory diseases (PID).
Just like the copper coil, this one can also be removed at any time, allowing for a swift return to fertility.
Side effects are somewhat more likely to happen when compared to the copper coil, however they remain quite uncommon because the hormones stay mostly in the uterus.
In general, they tend to appear in the first 3-6 months and go away, but overall they remain less prominent than with the pill or any contraceptive that injects hormones into the bloodstream.
Side effects then range from headaches to mood swings, increase in acne, breast tenderness, nausea and irregular bleeding (especially during the first 3-6 months)
As for the problem of the coil becoming dislodged and being pushed out of your body, it happens in 20% of cases and mostly in the first three months. Risk factors that increase the chances of expulsion are the same as for copper-based intrauterine contraception, e.g. women who have never been pregnant, tend to have heavy periods, are age below 20 and have already expelled an IUD before.
Your doctor may find that you are not suitable to use the hormonal contraceptive coil if you: