ring the third through the ninth months after fertilization, a developing human is called a(n) .

During the third through the ninth months after fertilization, a developing human is referred to as a "fetus."

The fetal stage is characterized by significant growth and development. It begins at the end of the embryonic period, approximately eight weeks after fertilization, and continues until birth. During this time, the developing fetus undergoes crucial developments, including the formation of organs and systems that are necessary for survival outside the womb.

By the end of this stage, the fetus has developed all major organ systems, and by the ninth month, it is usually fully matured and prepared for birth. The fetal stage is critical as it can impact the health of the newborn, with factors such as nutrition, maternal health, and environmental influences playing significant roles in fetal development.