Stillbirths from Adrenal Demedullated Mice Subjected to Chronic Stress Throughout Gestation

A paucity of experimental data exists relating the effect of chronic stress experienced throughout gestation to the incidence of stillbirths. Dornhorst & Young (1952) demonstrated that low, pressor dosages of epinephrine and norepinephrine administered intravenously to gravid rabbits and guinea-pigs produced vigorous uterine contractions with concomitant cyanosis of the placenta and decreases in both foetal heart-rate and blood-pressure. They interpreted their findings as indicating the action of these hormones to be on the placental vasculature and not the blockage of uterine vessels supplying the placenta. Since the secretion of the adrenal medullary hormones is part of the organism's stress response, the findings of the Dornhorst & Young investigation provide evidence for a mechanism which might be used to account, in part or whole, for the deleterious effects to prenatal development arising from maternal stress. The present investigation undertook to test this hypothesis by determining the incidence of stillbirths from adrenal demedullated and non-adrenal demedullated mice subjected to stress throughout gestation or allowed a stress-free gestation.