PIP: This article presents guidelines for physicians in the management of pregnancy with IUD in situ. If the failure rate of the typical IUD is assumed to be 2-3%, then 300,000-450,000 such pregnancies can be expected each year. If a woman wishes to continue with her pregnancy, the physician must assess whether the IUD should be removed. Localization of the IUD is an important 1st step in this process. When pregnancy occurs with an IUD in place, implantation generally is away from the device and the IUD remains extra-amniotic. Ultrasonography can localize both the IUD and the gestational sac. If the IUD is left in place, the risk of spontaneous abortion may be as high as 50%. Tailed IUDs yield a slightly higher abortion rate, but their removal appears to improve the chance for a live birth. The abortion rate in women with tail-less devices was found in 1 study to be even higher after extraction of the device than before manipulation. Another study compared the abortion risk in 120 women who had their IUD removed in the 1st trimester of pregnancy and 81 women whose IUD's were extracted. The abortion rate was 48% in the former group and 29% in the latter group. Yet another study recorded a 57% rate of fetal loss among 82 women who conceived with an IUD in situ, the majority of which occurred during the 2nd trimester.