From menses to ovulation: the immunomodulatory role of monocyte cytokines in menstrual cycle physiology and reproductive health - a narrative review.

Monocytes, as essential components of the immune system, play a pivotal role in regulating immune responses throughout the menstrual cycle. Their cytokine secretion is integral to immune modulation, influencing processes like endometrial remodeling, ovulation, and implantation. Cytokines such as interleukins, tumor necrosis factor (TNF), and growth factors secreted by monocytes help maintain a delicate balance between inflammation and immune tolerance, crucial for reproductive health. This balance facilitates both tissue repair and immune protection, ensuring proper function of the reproductive organs during the menstrual cycle. Dysregulation in monocyte cytokine secretion can contribute to a range of reproductive disorders, including endometriosis, polycystic ovary syndrome, and recurrent pregnancy loss. An overproduction of pro-inflammatory cytokines, such as TNF-α and interleukin-6, may lead to chronic inflammation, tissue damage, and impaired fertility. Conversely, inadequate secretion of anti-inflammatory cytokines can hinder the immune tolerance necessary for embryo implantation, potentially leading to complications like miscarriage. This review explores the pivotal role of monocytes and their cytokine secretion in maintaining reproductive health and their contribution to reproductive disorders.