What is true about cardiovascular system changes in a pregnant female patient?

During pregnancy, significant cardiovascular adaptations occur to support the growing fetus and accommodate the increased metabolic demands of the mother. One of the key changes is the increase in heart rate, typically by 10 to 15 beats per minute. This increase in heart rate helps to enhance cardiac output, which is crucial because blood volume rises significantly during pregnancy. By increasing the heart rate, the body ensures that adequate blood flow reaches the uterus and the developing fetus, along with meeting the nutritional and oxygen needs of the mother.

The other options do not accurately depict the physiological changes observed during pregnancy. For example, blood pressure typically decreases rather than increases in the first trimester due to hormonal influences and changes in vascular resistance. Additionally, plasma content actually increases, contributing to blood volume expansion. Lastly, cardiac output does not decrease; instead, it usually increases significantly to accommodate the needs of both the mother and the fetus throughout the pregnancy. Understanding these changes is important for EMTs and healthcare providers when assessing and managing pregnant patients.