Postnatal effects of oral administration of ethylenethiourea to rats during late pregnancy.

Ethylenethiourea (ETU), a manufacturing, processing, and metabolic product of the ethylenebisdithiocarbamate fungicides, was evaluated for its effects on postnatal performance of rats. ETU was given to pregnant rats as a single oral dose of 1-50 mg/kg on day 17, 18, 19, or 20 of gestation. The number of stillborn rats was significantly increased at dose levels of 30 and 50 mg/kg. Treatment of dams with 50 mg/kg on day 20 of gestation caused reduction in the birth weight of the offspring. Progeny survival was impaired after maternal treatment with doses of 10 mg/kg and more. The high mortality was attributable to the development of hydrocephalus in the pups. At 6 months of age, 16 and 26% of the surviving offspring from dams treated with 10 or 20 mg/kg had hydrocephalus.