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.