What is one of the primary purposes of estrogen during pregnancy?

One of the primary purposes of estrogen during pregnancy is to stimulate uterine development. Estrogen plays a crucial role in preparing the uterus for the growing fetus. It promotes the growth of uterine muscle cells and enhances blood flow to the uterus, creating an optimal environment for fetal development. This hormone also contributes to the maturation and maintenance of the uterine lining, which is vital for implantation and for providing nourishment to the embryo. The increase in uterine size is essential for accommodating the developing baby as it grows throughout the pregnancy.

In contrast, while increased blood pressure and managing morning sickness are aspects of pregnancy, these are not direct roles of estrogen. Additionally, fetal hair growth is not a primary function related to estrogen's role during gestation. Thus, the stimulation of uterine development is a clear and significant purpose of estrogen in the context of pregnancy.