Perforation of the uterus occurs after up to 2 per 100 insertions1, though rates are much lower for experienced operators2. For the earlier large plastic type of IUCD, insertion up to 8 weeks after delivery was followed by perforation at higher rates1, but the currently more popular small copper-on-plastic devices can be inserted between 4 and 8 weeks post-partum without increased rate of uterine perforation3. Technically, the greater safety may be attributed to the recommended method of inserting the loaded device to the top of the uterine cavity then withdrawing the insertion tube4.
Most perforations are believed to take place during insertion but can occur much later. Symptoms, which should alert the physician to immediate removal, are undue pain and heavy bleeding. Pain is, however, a judgment call, because apprehension and anxiety may cause a woman to experience the procedure as painful and to faint, even though there is no evidence of injury. Furthermore, perforation is commonly painless.
Signs of perforation at the time of insertion are sudden loss of resistance, and depth greater than vaginal examination would indicate.
The subsequent presence or absence of the attached tail-string in the vagina is not a reliable indicator of the absence or presence of perforation, though missing strings should always be investigated5.
Complications of uterine perforation include a considerably higher pregnancy rate than the cumulative 2-3% 10-year failure rate6 for a correctly positioned copper IUCD. The potential for sterile abscess and damage to internal organs warrants the removal of a IUCD that has perforated the uterus.