The outcome of 82 pregnancies associated with failure of an intrauterine device is reported. Four of the pregnancies were extrauterine, and 31 per cent of the 78 intrauterine pregnancies were legally terminated. Spontaneous or missed abortion occurred in 57 per cent of the remainder and over half of these abortions were in the second trimester. Threatened abortion, antepartum haemorrhage and manual removal of an adherent placenta were encountered more frequently than expected. One neonatal death due to prematurity was recorded, and there was one congenital fetal abnormality.