Tubal infertility and the intrauterine device

To study the association between intrauterine devices (IUDs) and pelvic inflammatory disease, we compared contraceptive histories in 4185 while women--283 nulliparous women with primary tubal infertility, 69 women with secondary tubal infertility, and 3833 women admitted for delivery at seven collaborating hospitals from 1981 to 1983. The relative risk of tubal infertility associated with IUD use was calculated by means of multivariate logistic regression to control for confounding factors, including region, year of menarche, religion, education, smoking, and reported number of sexual partners. The adjusted risk of primary tubal infertility associated with any IUD use before a first live birth was 2.0 (95 per cent confidence limits, 1.5 to 2.6) relative to nonuse. Users of the Dalkon Shield had an adjusted risk of 3.3 (1.7 to 6.1), users of the Lippes Loop or Saf-T-Coil had a risk of 2.9 (1.7 to 5.2), and users of copper IUDs had a risk of 1.6 (1.1 to 2.4). Women who reported having only one sexual partner had no increased risk of primary tubal infertility associated with IUD use. The adjusted risk of secondary tubal infertility associated with use of a copper IUD after a first live birth was not statistically significant (1.5; 95 per cent confidence limits, 0.8 to 3.0), whereas the risk from similar use of noncopper devices was significant (2.8; 1.3 to 5.9). We conclude that tubal infertility is associated with IUD use, but less so with copper IUDs.