An intrauterine device (IUD) is a common form of long-term contraception that involves a plastic or copper device placed in the uterus to hinder the passage of sperm through it. Although IUDs are one of the most effective forms of reversible birth control on the market, about 1 in 200 women with an IUD will become pregnant each year. Some such pregnancies will be ectopic, in which case the pregnancy must be terminated; non-ectopic pregnancies conceived with an IUD in place may theoretically be continued, if the mother wants to try to keep the baby.
But what's the risk of miscarriage if you get pregnant with an IUD in place?
Here is what UpToDate, an online reference site for doctors and patients, has to say about the odds of miscarriage in pregnancy with a failed IUD:
"The risk of pregnancy is highest in the first year after IUC (intrauterine contraception) insertion. Among women who conceive with an IUC in situ, the spontaneous abortion rate is 40 to 50 percent, a rate more than two-fold higher than that of the general obstetric population. A retained IUC also increases the risk of several late gestational adverse maternal and neonatal outcomes; this risk is reduced, but not eliminated, with early removal of the IUC."
So, in other words, there's unfortunately a higher than average chance of miscarriage in a non-ectopic pregnancy conceived with an IUD in place -- but there's also an equal or slightly higher chance that the pregnancy will not miscarry.
There's also an increased risk of other problems in later pregnancy with these pregnancies, but removing the IUD in early pregnancy reduces those risks and boosts the odds of a better outcome. With the benefits of early IUD removal added to the need to screen for ectopic pregnancy, it's wise to contact your doctor at once if you discover that you're pregnant with an IUD.
More questions? Read on.
Isn't there a strong chance that the pregnancy would be ectopic?
It is true that the risk of ectopic pregnancy is higher if you get pregnant with an IUD in place. The risk of any kind of pregnancy is lower in women with an IUD than in women not using contraception, but ruling out ectopic pregnancy is another reason why you should see a doctor right away if you discover you're pregnant with an IUD in place.
How is the IUD removed?
The doctor may carefully remove the IUD by pulling on the strings, if they are visible. If the strings are not visible, the doctor may attempt to locate the IUD by ultrasound and remove it with ultrasound guidance, if it seems like it will be safe to do so.
Couldn't the IUD removal process hurt the baby?
In some cases, it can, which is why you should talk to your doctor. Don't attempt to pull on the strings to remove the IUD yourself.
Can a pregnancy be continued with an IUD in place?
Sometimes, a doctor may advise against IUD removal. An example of such a case would be if the IUD appears to be embedded in the placenta. In these cases, the pregnancy may be continued with the IUD in place, but there's a higher risk of later pregnancy complications (such as premature birth) than in cases where it is possible to safely remove the IUD. In any case, your doctor will advise you on the best course of action after examining you.
Want to learn more? See UpToDate's topic, "Management of problems related to intrauterine contraception," for additional in-depth medical information.
Dean, Gillian and Alesa B. Goldberg. "Management of problems related to intrauterine contraception." UpToDate. Accessed: May 2010.