Which two hormones are primarily secreted by the placenta during pregnancy?

During pregnancy, the placenta plays a crucial role in hormone production to support the developing fetus and maintain the pregnancy. Among the hormones secreted, progesterone and estrogen are the primary ones.

Progesterone is essential for maintaining the uterine lining, which is crucial for implantation and the sustenance of the embryo/fetus. It helps to prevent contractions of the uterus and contributes to the overall maintenance of pregnancy. As pregnancy progresses, the placenta takes over the production of progesterone from the corpus luteum, which is important for sustaining the pregnancy until the placenta can assume full responsibility.

Estrogen, on the other hand, is also significant in preparing the mother's body for pregnancy and supporting fetal development. It plays an important role in the growth of uterine tissue, regulates other hormones, and helps with the development of the mammary glands in preparation for breastfeeding.

Thus, the correct option emphasizes the critical roles of both progesterone and estrogen during pregnancy, highlighting the importance of these hormones produced by the placenta. This understanding is central to the study of pregnancy physiology in public health nursing.