Final answer:
The hormone essential for maintaining pregnancy is progesterone, which inhibits new follicle development and reduces uterine contractions, creating a stable environment for fetal development.
Step-by-step explanation:
Which Hormone is Essential for Maintaining Pregnancy?
The hormone essential for maintaining pregnancy is progesterone. Progesterone is a female sex hormone secreted mainly by the ovaries. It plays a crucial role in maintaining a successful pregnancy by preventing new ovarian follicles from developing and suppressing uterine contractility, which ensures that an environment is conducive to fetal development. Additionally, progesterone stimulates the production of decidual cells of the endometrium that nourish the blastocyst before placentation.
Other hormones like estrogen and human chorionic gonadotropin (hCG) secreted by the corpus luteum and later by the placenta also support different aspects of pregnancy. Estrogen maintains the pregnancy, promotes fetal viability, and stimulates tissue growth in the mother and developing fetus. Meanwhile, hCG promotes progesterone synthesis and reduces the mother's immune function to protect the fetus from immune rejection.
However, when it comes to specifically maintaining the pregnancy and preparing the endometrium for potential implantation, progesterone is the key hormone responsible for these functions.