title: Thyroid hormone receptors and reproduction.
abstract: Thyroid disorders have a great impact on fertility in both sexes. Hyperthyroidism and hypothyroidism cause changes in sex hormone-binding globulin (SHBG), prolactin, gonadotropin-releasing hormone, and sex steroid serum levels. In females, thyroid hormones may also have a direct effect on oocytes, because it is known that specific binding sites for thyroxin are found on mouse and human oocytes. There is also an association between thyroid dysfunction in women and morbidity and outcome in pregnancy. In males, hyperthyroidism causes a reduction in sperm motility. The numbers of morphologically abnormal sperm are increased by hypothyroidism. When euthyroidism is restored, both abnormalities improve or normalize. In women, the alterations in fertility caused by thyroid disorders are more complex. Hyper- and hypothyroidism are the main thyroid diseases that have an adverse effect on female reproduction and cause menstrual disturbances--mainly hypomenorrhea and polymenorrhea in hyperthyroidism, and oligomenorrhea in hypothyroidism. In recent studies, it has become evident that it is not only changes in serum levels of SHBG and sex steroids that are responsible for these disorders, but also alterations in the metabolic pathway. Adequate levels of circulating thyroid hormones are of primary importance for normal reproductive function. This review presents an overview of the impact of thyroid disorders on reproduction.
authors.affiliation: Department of Obstetrics and Gynecology, Erlangen University Hospital, University of Erlangen-Nuremberg, Universitätsstrasse 21-23, D-91054 Erlangen, Germany. ralf.dittrich@uk-erlangen.de
authors.forename: Ralf
authors.initials: R
authors.lastname: Dittrich
authors.forename: Matthias W
authors.initials: MW
authors.lastname: Beckmann
authors.forename: Patricia G
authors.initials: PG
authors.lastname: Oppelt
authors.forename: Inge
authors.initials: I
authors.lastname: Hoffmann
authors.forename: Laura
authors.initials: L
authors.lastname: Lotz
authors.forename: Torsten
authors.initials: T
authors.lastname: Kuwert
authors.forename: Andreas
authors.initials: A
authors.lastname: Mueller
mesh_terms: D000818:Animals; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000503:physiopathology; D007037:Hypothyroidism / Q000503:physiopathology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000503:physiopathology; D011988:Receptors, Thyroid Hormone / Q000378:metabolism*; D012098:Reproduction; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism
chemical_list: D011988:Receptors, Thyroid Hormone; D012738:Sex Hormone-Binding Globulin