Technical failures in female sterilization using the tubal ring: a case-control analysis

To delineate characteristics of women predisposing to sterilization technical failures, we performed an analysis of 20 technical failures that occurred during tubal ring procedures and 80 control ring procedures matched on planned surgical approach and study site. None of the women had recently been pregnant (interval procedures). The odds ratios (ORs) were elevated for women wearing an IUD in the three months prior to sterilization (OR = 5.0, 90% confidence interval [CI] 2.2, 11.2) and for women with a history of spontaneous abortion (OR = 4.3, 90% CI 1.8, 9.8). A history of pelvic inflammatory disease (PID) and/or current evidence of PID was strongly associated with technical failure (X2 = 25.0, p less than 0.001). The combined effect of any two of these three factors increased the risk synergistically. We examined these factors prospectively and confirmed the elevated risks (relative risk [RR] = 5.0, 5.5 and 22.7 for recent IUD wearing, spontaneous abortion history and history/evidence of PID, respectively). The prospective analysis also found that previous abdominal surgery is associated with technical failure (RR = 6.7).