Intrauterine Device Failure: Relation to its Location Within the Uterine Cavity

OBJECTIVE:To investigate the possible role of position of the intrauterine device (IUD) in accidental pregnancies. METHODS:We examined the location of the IUD in 97 normal women 45-60 days post-insertion, and in 25 pregnant women with the device in situ. RESULTS:A cervically located IUD was identified in seven of 97 women (7.2%) after insertion and in 13 of 25 pregnant women (52%) with the device in situ. The odds ratio for a woman with an intracervical IUD to be pregnant compared with a woman with an IUD in the uterus was 13.93 (95% confidence limits 4.13-48.96). Sonographic follow-up of the pregnant women revealed no change in IUD location during early gestation. CONCLUSIONS:We suggest that cases of failed contraceptive action of the IUD may be secondary to a malpositioned device. A sonographic survey can identify displaced devices. Reinsertion of the IUD in such cases is recommended. (Obstet Gynecol 1993;81:112-4)