UTERINE perforation by an intrauterine contraceptive device (IUD) can be complete or partial. In complete perforation, the ectopic IUD is in the peritoneal cavity, either lying free, often in the posterior cul-de-sac, or adherent to uterus, adnexa, or peritoneum, or frequently enmeshed in omentum. Complete perforation— type 3—is usually diagnosed easily and the IUD is readily removed by laparoscopy, laparotomy, or colpotomy.
In partial perforation, the IUD may impinge on the uterus in different areas and in varying degrees. It may be classified according to the compartments involved, considering the uterine cavity as compartment 1, the myometrium as compartment 2, and the peritoneal cavity as compartment 3. Thus, in type 1-2 partial perforation, the IUD is partially in the uterine cavity and partially in the myometrium; in type 2, in the myometrium only; in type 2-3, in the myometrium and peritoneal cavity; and in type 1-2-3, in the uterine cavity,
Zakin D, Stern WZ, Rosenblatt R. Perforated and Embedded Intrauterine Devices. JAMA. 1982;247(15):2144-2146. doi:10.1001/jama.1982.03320400056038