Infertility and Thyroid Disorders

Thyroid disorders are quite prevalent in the population of reproductive age [1,2], four to five times more frequent in women than men. Both hyper- and hypothyroidism may result in menstrual disturbances, an increased risk of miscarriage, possible long-term health effects in the off- spring and spermatogenetic abnormalities [3]. Thyroid autoimmunity (TAI) is more prevalent in infertile women, especially in those with endometriosis, but the conception rate does not seem to be affected by the presence of antibodies nor by thyroxine treatment.

TAI is associated with an increased miscarriage rate but thyroxine treatment does not appear to play a protective role. Sufficient data on subclinical hyperthyroidism,
hypothyroidism and isolated TAI in infertility are lacking. A review of current information on the relation of thyroid disorders and infertility seems relevant and timely in order to review recent knowledge, as well to highlight areas, where evidence is not yet sufficient. Since radioiodine continues to be used widely in hyperthyroidism and thyroid cancer, its updated role in infertility is also included in this review.

Purpose of Review

This review highlights the ‘gap’ in knowledge regarding the contribution of thyroid dysfunction in reproduction. Thyroid dysfunction, which is quite prevalent in the population affects many organs including the male and female gonads, interferes with human reproductive physiology, reduces the likelihood of pregnancy and adversely affects pregnancy outcome, thus becoming relevant in the algorithm of
reproductive dysfunction.