Hormonal implants and intrauterine devices (IUDs) are both safe and dependable methods of birth control.
How They’re Alike
Both IUDs and implants are very effective -- your chance of getting pregnant is less than 1 in 100 the first year you use it. Compare that with nearly 10 in 100 women who get pregnant the first year they use birth control pills.
Implants and IUDs are alike in other ways too. A doctor or nurse has to insert and remove them -- you can’t do it yourself. Both are reversible -- you can get pregnant as soon as they’re removed. They’re more expensive at first than other kinds of birth control, but that cost evens out over time.
Also, neither method prevents STDs.
How They Compare
An IUD is a tiny T-shaped device that goes inside your uterus. There are 2 types: hormonal and copper.
The hormonal IUD releases the hormone progestin into your body. It prevents pregnancy by making the mucus in your cervical canal too thick for sperm to get through, by stopping your ovaries from releasing eggs, and by preventing a fertilized egg from attaching to the lining of your uterus. The copper IUD is wrapped in thin copper wire that’s toxic to sperm. It also keeps a fertilized egg from implanting in the uterus.
A hormonal implant is a tiny tube about the size of a matchstick that goes under the skin of your upper arm. It releases a small amount of progestin to stop your ovaries from releasing eggs and make the mucus in the cervix too thick for sperm to get through.
How long do they work?
A hormonal IUD works for between 3 and 5 years, depending on the brand. A copper IUD works for up to 10 years. An implant works for up to 3 years.
How soon do they start working?
Copper IUDs start to work as soon as they’re inserted. The hormonal kind will work right away if you put it in during the first 7 days of your period. Otherwise, it may take up to 7 days to prevent pregnancy.
How are they inserted?
Before you get an IUD, your health care provider will test you for STDs. Putting one in when you have an STD could cause pelvic inflammatory disease, a serious infection. Your provider may also test you to make sure you’re not pregnant.
The nurse or doctor will use a special tool to put the IUD through the opening in your cervix and into your uterus. It usually takes just few minutes. You may have cramps, but only for a minute or two. The IUD has strings attached that your provider can use to remove it later.
To insert an implant into your arm, your provider will first inject medicine that numbs the spot where it will go. Then they use a special device to place the implant under your skin. It only takes a few minutes, and no stitches are needed. They can also tell you how to care for the skin in that area in the days after you get the implant.
Usually, you can’t see the implant under your skin, but you’ll be able to feel it with your fingers. The spot may be sore for a few days, and bruising may occur.
After you get a hormonal IUD, your cramps may hurt less and your period may be lighter. Side effects like irregular periods and spotting between periods can happen but usually go away in 3 to 6 months. Copper IUDs can cause heavy bleeding, cramps, and bleeding between periods.
Implants can make your period very light or go away, and ease cramps and pain. The most common side effect is spotting in the first 6 to 12 months. Other side effects like headaches, weight gain, and mood changes can happen but aren’t very common.
Heavy bleeding isn’t normal with an implant. If that happens, keep track of how many pads or tampons you use and call your doctor right away.
Don’t use either kind of IUD if you:
- Have vaginal bleeding when you’re not on your period
- Have cancer of the cervix or uterus
- Have AIDS
- Are pregnant or want to get pregnant
- Have breast cancer
- Have liver tumors
- Liver disease
- Increased risk for STD/PID
- Abnormal uterine anatomy
Don’t use a hormonal implant if you:
What problems can happen?
Problems after you get an IUD are really rare but can happen. The IUD could push through the wall of your uterus. If it happens when your doctor is putting it in, they can fix it right away. If it isn’t fixed right away, the IUD could damage nearby organs, so it will have to be taken out.
In rare cases, you might get pregnant while using an IUD. There’s a higher chance that you could have an ectopic pregnancy, when the baby develops outside the uterus. This is a medical emergency. Call your doctor right way if you have sharp or cramping pain low in your stomach that lasts more than a few minutes.
The IUD can come out by itself, and you may not feel it happen. Get in touch with your doctor if you:
- Can’t feel the IUD strings
- Can feel the IUD in your cervix
- Have fluid or odor coming from your vagina
- Have persistent pain
Sometimes an implant can move inside your arm, or start to come out, usually in the first month after you get it. If you notice your implant coming out, start using another birth control method right away and see your doctor as soon as possible.
How are they removed?
Depending on the type you have, make sure to see your health care provider to have your IUD removed when it’s time (3 to 5 years for hormonal, and 10 years for copper).
If you get an implant, make an appointment after 3 years to have your provider take the implant out.
When your IUD or implant is removed, you can get a new one inserted at that time if you want.