Prolonged gestation associated with cyclopia in offspring of ewes ingesting Veratrum californicum is described. In single or multiple pregnancies where all foetuses are cyclopic, foetal hypophysial aplasia, foetal thyroidal and adrenal hypoplasia, and foetal gonadal hypertrophy were associated with prolonged gestation. Cyclopic foetuses that were twins to normal foetuses were delivered at term and, with the exception of hypophysial aplasia, other endocrine organs (thyroid, adrenal and gonads) showed no morphologic abnormalities.
In sheep, during prolonged gestation, comparative studies of the ability of maternal and foetal endocrine glands to synthesize steroids indicated that the foetal ovary was capable of transforming more substrates (pregnenolone and progesterone) into steroid metabolites than the maternal ovary, even though the same group of metabolites is formed by foetal and maternal ovaries. Foetal adrenals produced more testosterone than maternal adrenals, but synthesized very little cortisol, corticosterone and cortisone. Foetal adrenals were incapable of forming water-soluble steroids although the ovaries from cyclopic foetuses and maternal adrenals possessed this capability.