Evidence against tailstrings increasing the rate of pelvic inflammatory disease among IUD users.

A meta-analysis was conducted to determine whether the presence of an IUD tailstring is associated with increased rates of pelvic inflammatory disease among IUD users. Included were seven clinical studies that compared the same IUD with and without a tail, and fifteen clinical studies that compared two similar copper IUDs that differed in the polymer used for the tailstring (polypropylene versus polyethylene). No increase in PID rates was found among users of IUDs with versus without a tail (RR = 1.2, 95% confidence interval 0.6-1.7), or among users of copper IUDs with different tailstring materials (polypropylene vs. polyethylene, RR = 0.9, 95% confidence interval 0.4-1.5). These findings support the hypothesis that the presence of a tailstring does not increase the rate of PID among users of IUDs.