Periods may also be much heavier with IUDs, and you'll either get more severe cramps or develop cramps. Because of this, anemia is common in IUD users. IUDs have also been linked to uterine and cervical cancer, but this area is still murky. About 15 percent of IUD users have them removed because of bleeding, spotting, hemorrhaging, or anemia. Often, though, expulsion is painless.
Lost strings are another problem, making removal difficult.
Full-term pregnancies have been reported with an IUD in place, but if you do get pregnant while you have an IUD, there's a 30 percent chance you'll miscarry. If a miscarriage does occur, there's an increased risk of infection. Some of these infections can be fatal. Punctures in the uterus or cervix are another drawback to IUDs and can lead to pelvic infections. Insertion can be very painful.