What effect does increased estrogen have on the menstrual cycle?

• A. Inhibits ovulation
• B. Stimulates egg production
• C. Initiates menstruation
• D. Promotes thickening of the endometrium

Answer: (D)

Increased estrogen primarily promotes the thickening of the endometrium. During the follicular phase of the menstrual cycle, rising levels of estrogen are responsible for stimulating the growth and proliferation of the endometrial lining in preparation for a possible implantation of a fertilized egg. As the follicles in the ovaries mature and secrete estrogen, the endometrial cells respond by increasing in number and size, creating a suitable environment for potential pregnancy.

This physiological process is essential for establishing a supportive uterine environment should fertilization occur. If a pregnancy does not take place, levels of estrogen and progesterone drop, leading to the breakdown of this thickened lining, which ultimately results in menstruation. Thus, the role of increased estrogen in contributing to endometrial thickening is critical in the overall menstrual cycle and reproductive health.