The results of longitudinal study of a self-selected sample of 1,790 Barbadian women who accepted the intrauterine contraceptive device (IUD) as their method of contraception are reported. The accumulated experience of 44,000 woman months of IUD use is presented. The demographic, medical, and obstetric data on admission for 2,797 IUD acceptors and 4,296 nonacceptors are contrasted. The reproductive experience of the two groups prior to the insertion of an IUD with respect to live births, stillbirths, and miscarriages is similar while the incidence of ectopic pregnancy is shown to be different. The association between the IUD and the incidence of tubal pregnancy is evaluated, and the literature dealing with this topic is reviewed. Estimates of the relative risk of an ectopic pregnancy in a woman with an IUD in utero are given.