It is indeed possible to get pregnant with an intrauterine device (IUD) in place, because IUDs are not 100% effective at preventing pregnancy. Around 1 in 100 women get pregnant while using one, according to clinical trials conducted with IUDs, and the outcome of the pregnancy varies, depending on the woman, the IUD, and the situation. Due to the fact that pregnancy is a potential risk with an IUD in place, it is important for women to keep track of changes in their bodies while using is form of contraceptive, so that a pregnancy can be identified in the early stages.
An intrauterine device prevents pregnancy either by preventing sperm from reaching the egg, or by altering the uterine lining so that fertilized eggs cannot implant and develop into fetuses, making it difficult to get pregnant. Copper IUDs accomplish this by secreting copper into the uterus, while hormonal IUDs release progesterone. These devices are actually the most effective way to prevent pregnancy after abstinence, with hormonal birth control failing in 1 to 2% of cases, with a failure rate which is even higher when the pill is not used properly.
The advantage of an IUD is that it is very difficult to use it improperly, in contrast with other forms of birth control that may need to be taken every day or attended to prior to each sexual encounter. As long as a woman checks her IUD strings regularly, the device is considered to be in place and working. It is still possible to get pregnant with an IUD, however, because sperm are nothing if not determined, as is human life in general. Women with unusually large or small uteri may also be more likely to get pregnant than women with uteri that fit within the range of those tested during development of the IUD.
If a woman becomes pregnant while using an IUD, most doctors recommend that the device be removed so that it does not interfere with the pregnancy. In some cases, the removal may pose the risk of a miscarriage, in which case, it will be left as is. The IUD will not usually hurt the baby, but it can cause developmental abnormalities. In other instances, a woman may opt for an abortion because she does not feel ready to have a child. The pregnancy may also miscarry naturally, with the risk increased if the IUD is left in place.
One big risk of getting pregnant with an IUD is that use of the device increases the risk of an ectopic pregnancy, a pregnancy that takes place outside the uterus. This kind of pregnancy is extremely dangerous, and it requires immediate medical attention. Women who think that they have become pregnant while using an IUD should go to a medical professional to confirm the position and status of the pregnancy, no matter what they ultimately decide to do about it. Using condoms can also reduce the likelihood that a woman will get pregnant when using an IUD.