Graves’ disease and nodular toxic thyroid disease are the leading causes of hyperthyroidism. Iodine fortification (IF) among mild-to-moderate iodine deficiency populations is associated with transient increase in incident thyrotoxic nodular disease that may last up to 10 years. A rise in incident Graves’ disease and other autoimmune thyroid conditions has also been associated with IF. Epidemiological studies from different geographical settings around the globe suggest increased incidence even among reproductive age groups in affected populations. Recurrent iodine deficiency in iodine replete populations in developed countries may also predispose them to a similar phenomenon. The prevalence and consequences of hyperthyroidism in pregnancy may be higher than previously reported. We intend to describe the aetiopathology and epidemiology of hyperthyroidism, the mechanisms through which hyperthyroidism predisposes to infertility; the impact of hyperthyroidism on fertility treatment, pregnancy in general and among women with infertility; as well as the effects of hyperthyroidism or agents used in the treatment of hyperthyroidism on perinatal outcomes and adult life for those exposed in utero.