Tubal Occlusion Failures: Implications of the CREST Study on Reducing the Risk.

Through data reported in the US Collaborative Review of Sterilization (CREST) study, we have learned that 10-year cumulative failure rates of sterilization done by tubal occlusion are much higher than originally thought. While the small, earlier studies reported failure rates as low as 3 to 4 per 1000 procedures, they often followed women for only 2 years after the procedure. When pregnancies occurred during this period, the operative assumption was that these failures were due to incomplete occlusion. Most reports have not addressed the possibility of recanalization leading to failures. The CREST findings, however, suggest that failure rates are closer to 18 per 1000, depending on the occlusion method used and characteristics of the patient. This study also shed light on the factors that increase the risk of ectopic pregnancy after sterilization procedures. These new long-term data indicate that all providers should know that pregnancy, including ectopic pregnancy, can occur in women with history of tubal occlusion for sterilization, especially many years after the original procedure.