Neuroendocrine Causes of Amenorrhea-An Update

Context: Secondary amenorrhea-the absence of menses for three consecutive cycles-affects approximately 3-4% of reproductive age women, and infertility-the failure to conceive after 12 months of regular intercourse-affects approximately 6-10%. Neuroendocrine causes of amenorrhea and infertility, including functional hypothalamic amenorrhea and hyperprolactinemia, constitute a majority of these cases. Objective: In this review, we discuss the physiologic, pathologic, and iatrogenic causes of amenorrhea and infertility arising from perturbations in the hypothalamic-pituitary-adrenal axis, including potential genetic causes. We focus extensively on the hormonal mechanisms involved in disrupting the hypothalamic-pituitary-ovarian axis. Conclusions: A thorough understanding of the neuroendocrine causes of amenorrhea and infertility is critical for properly assessing patients presenting with these complaints. Prompt evaluation and treatment are essential to prevent loss of bone mass due to hypoestrogenemia and/or to achieve the time-sensitive treatment goal of conception.