What is the primary role of human placental lactogen (hPL) during pregnancy?

The primary role of human placental lactogen (hPL) during pregnancy is to facilitate glucose, minerals, and protein delivery to the fetus. This hormone, produced by the placenta, plays a crucial role in metabolic adaptations that ensure adequate nutritional supply to the developing fetus. hPL helps to modify the maternal metabolism, promoting the availability of nutrients by increasing maternal insulin resistance and enhancing the mobilization of fatty acids. This process ensures that the fetus receives sufficient energy and building blocks necessary for its growth and development.

While the other options reflect important aspects of maternal and fetal health during pregnancy, they do not represent the main function of hPL. Stimulating milk production is more directly related to prolactin, which primarily acts postpartum. Regulating maternal blood pressure is influenced by other hormonal changes throughout pregnancy, particularly involving the renin-angiotensin system. Although fetal brain development is essential, it is influenced by a variety of factors, including but not limited to the nutrients provided through the actions of hPL and other hormones.