IUD insertion can cause ectopic pregnancy because it is a minor gynecological surgery and an invasive procedure. Any invasive operation can potentially trigger pelvic inflammatory disease. The occurrence of pelvic inflammatory disease can lead to inflammation of the fallopian tubes, which is one of the main causes of ectopic pregnancy. Moreover, not every patient is suitable for an IUD. These devices come in many shapes, and there should be an optimal match between the shape of the IUD and the size and form of the uterine cavity. If the IUD does not match the patient's uterine cavity size and shape, it may not effectively prevent pregnancy, thus increasing the risk of pregnancy with the IUD in place, including the occurrence of ectopic pregnancies. In conclusion, IUD insertion can lead to ectopic pregnancies.