What role does estrogen play in the female reproductive system?

Estrogen plays a crucial role in the female reproductive system, particularly in regulating the menstrual cycle and supporting pregnancy. Throughout the menstrual cycle, estrogen levels fluctuate, influencing various physiological processes. It is responsible for the development and maintenance of female secondary sexual characteristics, such as breast development and the regulation of the menstrual cycle itself.

During the follicular phase of the cycle, estrogen promotes the thickening of the endometrial lining in preparation for potential implantation of a fertilized egg. If pregnancy occurs, estrogen continues to support the maintenance of the uterine environment conducive to fetal development. It also works together with other hormones to prepare the body for childbirth and lactation.

This role of estrogen is foundational for female reproductive health, illustrating why it is integral to both the menstrual cycle and the early stages of pregnancy.