Effects of gestational stress: 1. Evaluation of maternal and juvenile offspring behavior

In both humans and animals, stress experienced during gestation is associated with physiological changes and disruptions in emotional function and cognitive ability in offspring; however, much less is known about the effects of such stress in mothers. In animal models, physical restraint is commonly employed to induce stress during gestation and results in elevated postpartum maternal anxiety and changes in maternal care. The purpose of the current study was to evaluate the consequences of restraint stress applied on gestation days 10 through 19 in mother rats and their juvenile offspring. Progeny were reared by birth mothers. Preterm anxiety was assessed in the elevated plus maze and maternal behavior in the retrieval test. Cognitive (T-maze) and anxiety measures (elevated plus maze and emergence) were applied to a subset of male and female offspring at 30–31 days of age. Weight and litter characteristics were also recorded. Mother rats exposed to stress during gestation had attenuated weight gain, elevated anxiety-like behavior, and reduced maternal care. Stressed mothers also had fewer pups and an elevated offspring mortality rate. The consequences of gestational stress in offspring were subtle and gender-dependent. Only juvenile females displayed marginal effects of gestational stress in the form of elevated anxiety-like behavior and attenuated weight gain. In the current study, although gestational stress had robust effects in the mother rat, these did not translate to similar changes in offspring behavior. The importance of focusing research on maternal responses to gestational stress is highlighted by these findings.