Dept. of Pharmacology & Toxicology, University of Rochester, School of Medicine and Dentistry, New York.

Fetal death in rats was produced by subcutaneous injections of CdCl2 (40 mumoles/kg) on day 18 of pregnancy. The incidence of fetal death following these maternal injections was 74.9%, with mean (+/- SD) fetal cadmium burdens of 8.6 +/- 4.4 nmoles. To separate maternal from fetal effects of cadmium, doses of CdCl2 up to 60 mumoles/kg fetal weight were injected directly into fetuses on day 18 of gestation. Fetal viability was then determined on gestational day 21. Following direct fetal injection, mean fetal body burdens of cadmium were 74.6 +/- 34.8 nmoles, but the incidence of fetal dealth was only 11.5%. The high incidence of fetal death following maternal exposure to CdCl2 is not solely explained by the direct effects of CdCl2 on the fetus. Thus, the fetal toxicity of cadmium may be the result of some extra-fetal mechanism such as maternal toxicity or the observed placental necrosis.