What is one primary role of estrogen during pregnancy?

The primary role of estrogen during pregnancy is to stimulate uterine development for the fetus. Estrogen is crucial in promoting the growth and development of the uterine lining, which is essential for providing a nourishing environment for the growing fetus. It enhances blood flow to the uterus and promotes the enlargement of uterine cells, which ultimately supports the expanding needs of the fetus as it develops throughout pregnancy.

This increase in uterine size and blood supply is vital for healthy fetal growth, as it facilitates the exchange of nutrients and waste products between the mother and fetus. While the other choices present functions related to estrogen or pregnancy, they are not its primary roles. For instance, although estrogen influences metabolic processes and immune responses in a broader context, its most significant contribution during pregnancy centers on uterine adaptation and support of fetal development.