Bone Quality Analysis of the Effects of Maternal Prenatal Stress Exposure

Abstract

Unperturbed fetal development is essential for future health of an individual. Previous studies have linked diseases of aging to harmful alterations that happen during fetal development. Given the significant long‐term impact that intrauterine environment has on an individual's life, it was hypothesized that maternal stress during pregnancy will have negative effects on the offspring's bone density and cross‐sectional area. To test this, twenty‐eight female and seven male Wistar rats (Rattus norvegicus) were purchased and bred to produce 176 offspring. During pregnancy, dams were randomly divided into four groups (n=7, per group) and immobilization stress induced as follows; Group 1 (GW1): immobilization stress on days 1–7 of pregnancy, Group 2 (GW2): on days 8–14, Group 3 (GW3): on days 15–21, Group 4 (Controls): left undisturbed. Maternal cortisol hormone, food intake, and weight gain were monitored during pregnancy. Pups were raised under normal laboratory conditions and sacrificed at ages: 4, 8, 12, and 16 weeks to determine the effect of prenatal stress. At necropsy, the femur was removed and preserved for image analysis.Differences among groups were determined by T‐test or analysis of variance (ANOVA). P values ≤ 0.05 were considered significant. Cortisol hormone levels in controls were lower than those of stressed animals. Stressed dams consumed 12.5% less food per day compared to controls. Animals in GW1 and GW2 gained less weight during pregnancy but had larger litters than did GW3 or the control group. Offspring born to GW3 were heavier compared to all other groups. Preliminary MicroCT analysis of cortical bone shows the control males as having higher cortical thickness compared to male treatment groups at the age of 8 and 16 weeks. There was no significant difference in cortical thickness of females. Trabecular thickness in controls was higher at the age of 4 and 8 weeks compared to treatment groups. This difference was observed in both males and females. There was no significant difference observed among treatment groups. Analysis of the remaining samples is ongoing.Support or Funding InformationAmerican Association of Anatomists Visiting Scholarship.