Adlersberg & Burrow, 2001. Thyroid function and dysfunction in women

[Guest guest]

This article was written to teach doctors about treating thyroid dysfunctions in women. It is short, readable, and has a lot of interesting information on thyroid issues. It even discusses the effects of pregnancy on iodine metabolism. Zoe

Focus on primary care. Thyroid function and dysfunction in women.

Adlersberg MA, Burrow GN.

Obstet Gynecol Surv. 2002 Mar;57(3 Suppl):S1-7. Review.

"All forms of thyroid disease are more common in women. The reason for this gender predilection has not been entirely elucidated but may relate to the closely intertwined relationship between thyroid function and the female reproductive axis. Thyroid dysfunction influences both menstrual function and fertility, likely through changes in sex hormone levels, gonadotropin release, and possibly ovarian function. Similarly, alterations in reproductive physiology can modulate thyroid function. In such settings as pregnancy, when sex hormone levels fluctuate markedly, variations in thyroid function occur frequently. For the clinician, understanding when such alterations require intervention is critical.

TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians

LEARNING OBJECTIVES: After completion of this article, the reader will be able to describe the abnormalities of the female reproductive axis associated with both hypo- and hyperthyroidism, to summarize how female sex hormones affect thyroid function, and to explain the effects of pregnancy on thyroid conditions."

http://iodine4health.com/body/pregnancy/burrow_pregnancy.htm

"In addition to effects on TBG, pregnancy also leads to alterations in iodine metabolism, which can have important ramifications for thyroid hormone function. By stimulating an increase in glomerular filtration rate (GFR) pregnancy causes increased clearance of iodide by the kidneys.... In areas where iodine intake is low, frank iodine deficiency may result. Iodine levels may decrease even further during the latter half of gestation when the fetus begins to take up iodine from the maternal circulation to use in its own production of thyroid hormones....

"Iodine deficiency, particularly if severe, may lead to the development of hypothyroidism in the mother. This can present significant risks to the developing fetus, particularly during the early part of gestation and can result in neonatal hypothyroidism, defects in IQ and developmental abnormalities. Iodine deficiency also likely contributes to the formation of pregnancy-related goiter."

"Structural similarity [exists] between TSH, LH, and FSH. All three hormones share identical alpha-subunits, and up to 50% homology has been noted in their distinct beta-subunits. Such homology raises the possibility for cross-reactivity at the receptor level. If all three hormones can bind to each other's receptors, changes in one hormone level may affect the release of the other."