Thyroid disease in pregnancy. Foreword.

摘要

Interest in thyroid dysfunction complicating pregnancy has increased significantly in the past 2 decades. Pregnancy is associated with significant but reversible changes in maternal thyroid physiology that can lead to confusion in the diagnosis of thyroid abnormalities. Perhaps most relevant is the intimate relationship between maternal and fetal thyroid function, particularly during the first half of pregnancy. The fetal thyroid gland begins concentrating iodine and synthesizing thyroid hormone after 12 weeks' gestation. Although the fetus relies on the mother for iodine throughout pregnancy, thyroid hormones essential for fetal brain development are supplied by the mother in the first trimester with the fetus gradually generating its own as the pregnancy advances.