Background: Pregnancy is accompanied by substantial physiological and hematological adaptations that may be influenced by maternal stress. However, the hematological responses to varying types and intensities of stress during pregnancy, as well as the extent to which these maternal changes are reflected in the offspring, remain poorly understood.
Objectives: This study examined stress-induced alterations in hematologic indices in pregnant female Wistar rats and their offspring to unravel the pathological process involved in hematologic diseases.
Methods: Sixty (60) healthy female rats between 12 and 14 weeks old, weighing between 160 and 200 grams, were used for phase 1. At the end of each week, following exposure to the different stress model, the rats were euthanized and bled in the first, second, and third weeks, respectively, to estimate total white blood cell (TWBC), red blood cell (RBC), and platelet counts, packed cell volume (PCV), and hemoglobin (Hb) concentration. For the phase 2 of the experiment, twelve offspring were used, six from the control group of stressed parents and six from the intruder-stressed parents. Blood samples were collected from offspring of stressed parents 4 weeks after gestation to estimate hematologic indices. The study adopted restraint chamber, mirror chamber, and resident intruder stress models for stress induction.
Results: The different stressors studied caused a significant (P<0.05) reduction in TWBC and RBC counts, while PCV, Hb concentration and platelet counts increased. Apart from the TWBC count, where the value increased significantly (P<0.05), exposure to intruder stressor decreased PCV values and RBC and platelet counts. The mean values of the hematologic indices of the offspring of parents exposed to intruder stressor increased; however, the increase was significant (P<0.05) only with respect to PCV, Hb concentration, and platelet counts. Perhaps, in terms of the degree of intensity of the stressors, intruder stressors induced the highest intensity of stress in rats compared to the other stressors. The restraint stressor was the next, followed by mirror stressors.
Conclusion: In conclusion, the effect of stress on hematologic indices varies during different trimesters of pregnancy and this dependent on the nature, intensity, and duration of the stressor applied. However, the effects of stress during pregnancy on the blood parameters of pregnant mothers cannot be transmitted to their infants, especially in the case of the intruder stressor studied.