Physiological adaptations of pregnancy affect neurological function in health and disease. Women often experience self-limited sensory abnormalities that resolve shortly after delivery. More important, pregnancy can predispose to the onset or deterioration of permanent neurological disorders. Lastly, complications of pregnancy may develop in patients with preexisting neurological disease. Therefore, a basic knowledge of reproductive physiology can guide clinicians in the diagnosis and management of the pregnant patient with neurological symptoms. This clinical review highlights the modifications that affect the nervous system, including neuroanatomy, reproductive endocrinology, immunology, systemic and cerebral circulations, metabolism, and coagulation profile. The widespread role of sex steroids in many of these adaptations is addressed to illustrate the complex interactions of human reproductive biology.