The first risk, an ectopic pregnancy, means that the fertilized egg grows outside the uterus and the pregnancy occurs in the fallopian tubes instead. This is an emergency that requires immediate medical attention — if left untreated, ectopic pregnancy can cause internal bleeding, infertility, and even death.
If the fertilized egg successfully implants in the uterus and you continue the pregnancy with a hormonal IUD, there are different risks. These include infection or sepsis, says Gunter, and also miscarriage, premature delivery, or very rarely, death. However, just because these can happen doesn't mean they will happen.
"We do know there's a slightly higher risk of a negative outcome with the pregnancy if you still have a hormonal IUD, but we don't know how high or have any percentages because there just haven't been many studies on this yet," Gunter said. So if you have an IUD and think you're pregnant, don't panic — just go see your doctor as soon as possible.