THE MAJOR SOURCE OF ESTROGENS IN THE HUMAN FETUS IS

• A. The fetal ovary
• B. The fetal testis
• C. The fetal zone of the fetal adrenal cortex
• D. The definitive zone of the fetal adrenal cortex
• E. The placenta ✓

The major source of estrogens in the human fetus is the placenta. During pregnancy, the placenta produces estrogen hormones that are essential for fetal development and maintaining a healthy pregnancy. Estrogens play a crucial role in regulating various physiological processes in the fetus, such as organ development, bone growth, and reproductive system maturation.

Estrogens are a group of steroid hormones that include estradiol, estriol, and estrone. These hormones are primarily produced by the ovaries in adult females. However, during pregnancy, the placenta becomes a significant source of estrogen production to support the developing fetus. The placenta converts precursor hormones from the maternal circulation into estrogens through enzymatic processes.

Estrogens produced by the placenta are crucial for fetal growth and development. They help regulate gene expression, promote tissue differentiation, and influence the development of secondary sexual characteristics in both male and female fetuses. Additionally, estrogens play a role in maintaining uterine blood flow, supporting nutrient transfer to the fetus, and preparing the mother’s body for labor and delivery.

In summary, the placenta serves as the primary source of estrogens in the human fetus during pregnancy. These hormones are essential for fetal development and play a critical role in ensuring a healthy pregnancy.