Which hormone increase is most frequently responsible for decreased estrogen production due to pituitary adenoma?

The correct answer is the hormone that is most frequently responsible for decreased estrogen production due to a pituitary adenoma, which is prolactin. When a pituitary adenoma is present, it often secretes excess prolactin, a condition known as hyperprolactinemia. Elevated levels of prolactin can inhibit gonadotropin-releasing hormone (GnRH) release from the hypothalamus, leading to reduced secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary gland.

Since LH and FSH are crucial for ovarian function, including the production of estrogen, decreased levels of these hormones directly impact estrogen synthesis. The suppression of ovarian hormone production is significant, resulting in low estrogen levels and various symptoms, including menstrual irregularities and other endocrine dysfunctions. Prolactin's role in inhibiting the reproductive hormonal axis is a key mechanism in this process, underscoring its importance in conditions such as prolactinomas, a specific type of pituitary adenoma.