What physiological change allows the uterus to be palpable at the symphysis pubis?

The correct answer relates to the physiological change of uterine enlargement, which is a key factor that enables the uterus to be palpable at the symphysis pubis during pregnancy. As the pregnancy progresses, the uterus undergoes significant growth to accommodate the developing fetus. This enlargement is noticeable as the uterus expands upward and outward, effectively pushing against the abdominal wall and becoming accessible for palpation at the symphysis pubis, which is the joint located at the front of the pelvis.

Other factors, such as increased blood volume and hormonal changes, play important roles during pregnancy, but they do not directly result in the uterus being palpable at the symphysis pubis. Increased blood volume primarily supports enhanced circulation and nutrient delivery but does not contribute to the physical size of the uterus. Likewise, while hormonal changes are crucial for sustaining pregnancy and promoting uterine growth, they are not the direct cause of the uterus being felt at this specific anatomical point. Fetal movement may indicate a developing pregnancy, but it does not impact the ability to palpate the size or position of the uterus in relation to the symphysis pubis. Hence, uterine enlargement is the primary physiological change responsible for this palpable finding.