Effects of oral lynestrenol administration on prenatal and postnatal progeny development in rabbits.

Pregnant Belted Dutch rabbits were administered lynestrenol (17-alpha-ethynyl-oestr-4-en-17-beta-ol) orally on days 6-18 of gestation at a dose of 0.5 mg/kg/day. The dose littered on term and the surviving offspring were observed until four weeks old. Neurological disturbances characterized by behavioural abnormalities and locomotor disabilities were observed. About 40% of the offspring died within four weeks, and more than 70% of these had congenital malformations.