STRESS DURING PREGNANCY ALTERS RAT OFFSPRING MORPHOLOGY AND ULTRASONIC VOCALIZATIONS

Stress during pregnancy, or prenatal stress, is known to alter offspri ng behavior, morphology and physiology. We found that a heat, light an d restraint stressor applied during the third trimester of pregnancy: 1) decreased the weight gain of adult female rats during pregnancy; 2) reduced the weight of pups, as well as the anogenital distance of mal e offspring, at birth; and 3) increased the number of ultrasonic vocal izations emitted by pups during isolation in a novel environment on Po stnatal Day 14. These results closely approximate those we previously observed after peripheral administration of corticotropin-releasing fa ctor to pregnant females during the third trimester. Together, the stu dies strongly suggest a role for corticotropin-releasing factor and/or other hormones of the hypothalamic-pituitary-adrenal system in mediat ing some of the effects of gestational stress. (C) 1998 Elsevier Scien ce Inc.