Final answer:
Pregnant soldiers experience increased blood volume and changes in cardiovascular parameters, including a rise in pulse and blood pressure, to support fetal demands. Postpartum soldiers undergo a return to pre-pregnancy cardiovascular states and maintain or improve their ability to exercise with increased efficiency in cardiac output and blood pressure.
Step-by-step explanation:
The cardiovascular activity between pregnant and postpartum soldiers shows significant differences mainly due to physiological changes during pregnancy. Pregnant soldiers experience an increase in blood volume, up to 1-2 liters or about 30 percent above preconception volume, to support fetal nourishment and waste removal. This results in a moderate rise in their pulse and blood pressure. The growing uterus also compresses pelvic vessels, causing venous return issues which can lead to varicose veins or hemorrhoids. Fetal hemoglobin in the circulation differs as well, adapting to bind oxygen at lower pressures from the mother's blood via the placenta as the lungs are not used until birth.
In contrast, postpartum soldiers' cardiovascular systems gradually return to their pre-pregnancy state. Blood volume, heart rate, and blood pressure will start to normalize. The cessation of placental blood flow and the initiation of the newborn's lung function marks a shift back to adult circulation patterns. Furthermore, exercise influences cardiovascular activity differently postpartum. The heart of a well-trained athlete can increase cardiac output and blood pressure substantially during exercise as compared to a nonathlete, and tissue perfusion also significantly increases from rest to exercise.