Abstract:Thyroid dysfunction has a significant impact on reproduction. In women, hypothyroidism and thyrotoxicosis can cause menstrual disorders, ovarian failure, hypoplasia of the uterine, and adverse maternal and neonatal outcomes. In males, thyroid disorder can cause erectile dysfunction and sperm abnormality. Thyroid hormone insufficiency mainly affects sperm morphology and quality. Excessive thyroid hormone secretion is primarily related to abnormal sperm motility. Thyroid dysfunction also contributes to changes in sex hormone levels and has a negative impact on fertility. This article reviews the effects of thyroid function and thyroid autoimmunity on reproduction.