Mechanisms Linking Sleep Disturbances to Menstrual Cycle Irregularities, Infertility, and Dysmenorrhea in Women of Reproductive Age: A Systematic Review with Thematic Synthesis

This systematic review will synthesise the biological and epidemiological evidence describing how sleep disturbance is mechanistically linked to three reproductive outcomes in women of reproductive age: menstrual cycle irregularity, infertility/subfertility, and dysmenorrhea. Building on a preliminary narrative scoping of the field, the review will systematically identify, appraise, and thematically integrate studies that report circadian, neuroendocrine, and inflammatory pathways connecting disturbed sleep with reproductive dysfunction. The expected outcome is a structured, transparent evidence map of the mechanistic pathways (circadian/HPO-axis, melatonin/ovarian, HPA-axis/cortisol, inflammatory/pain, and hormone–sleep bidirectionality), an assessment of the strength and consistency of the underlying evidence, and an explicit translation of these mechanisms into implications for maternity and reproductive-health nursing assessment and practice. The review is intended to establish the biological plausibility and modifiability of sleep as a determinant of women’s reproductive health and to identify priority gaps for future longitudinal and interventional research.