Of the 8 pregnancies studied, 2 were of small gestational sacs with blighted ova and were associated with devices in which the copper wire had very high detectable X-ray emissions for copper (greater than 90%). In 2 other pregnancies intrauterine deaths had occurred by the time of termination at 13 and 17 weeks and copper levels in the products of conception were variable. There was no abnormality of the fetus in the term pregnancy but it seems possible that copper can affect the early growth and development of the embryo. On only 1 of the 8 devices was any great amount of calcium deposited and it is therefore considered unlikely that calcium deposition increases the risk of pregnancy by preventing the release of copper.