Detailed medical illustration of an intrauterine device (IUD) in the uterus preventing sperm from reaching the egg, demonstrating maximum protection against pregnancy. Visual guide to effective con...
When an IUD is correctly positioned at the top of the uterus, it is more than 99% effective at preventing pregnancy. The device works by interfering with sperm movement and survival, making fertilization extremely unlikely.
In rare cases, an IUD can move lower in the uterus or partially expel without obvious symptoms. When this happens, its effectiveness may decrease. Routine follow-up exams help ensure the device remains properly positioned.
If an IUD is displaced or expelled, fertilization can occur in the fallopian tube, as it normally would. Pregnancy with an IUD is uncommon, but when it does happen, there is a higher likelihood it may be ectopic — meaning it develops outside the uterus. Prompt medical evaluation is important if symptoms arise.