Controlled trials on infant neurodevelopment were lacking ; gestational iodine supplementation reduced maternal thyroid volume and serum thyroglobulin and in some studies prevented a rise in serum thyroid-stimulating hormone .
Iodine supplementation improves some maternal thyroid indices and may benefit aspects of cognitive function in school-age children , even in marginally iodine-deficient areas .
BACKGROUND Although the detrimental effects of severe iodine deficiency are well recognised , the benefits of correcting mild-to-moderate iodine deficiency are uncertain .
OBJECTIVES We undertook a systematic review of the impact of iodine supplementation in population s with mild-to-moderate iodine deficiency .
Increased pregnancy loss rate in thyroid antibody negative women with TSH levels between 2.5 and 5.0 in the first trimester of pregnancy.
CONTEXT The definition of what constitutes a normal TSH during pregnancy is in flux . Recent studies suggested that the first trimester upper limit of normal for TSH should be 2.5 mIU/liter . OBJECTIVE The objective of the study was to evaluate the pregnancy loss and preterm delivery rate in first-trimester thyroid peroxidase antibody-negative women with TSH values between 2.5 and 5.0 mIU/liter . DESIGN The present study is a component of a recently published large-scale prospect i ve trial that evaluated the impact of levothyroxine treatment on maternal and neonatal complications in thyroid peroxidase-positive women with TSH levels above 2.5 mIU/liter . The present study evaluated 4123 thyroid peroxidase antibody-negative women with TSH levels at or below 5.0 mIU/liter . Women were divided into two groups based on their initial TSH : group A , TSH level below 2.5 mIU/liter , excluding hyperthyroid women defined as an undetectable TSH with an elevated free T(4 ) , and group B , TSH level between 2.5 and 5.0 mIU/liter . SETTING The study was conducted at two ambulatory clinics of community hospitals in southern Italy . PATIENTS A total of 4123 women were evaluated . INTERVENTION There was no intervention . MAIN OUTCOME MEASURES The incidence of pregnancy loss and preterm delivery in group A as compared with group B was measured . RESULTS The rate of pregnancy loss was significantly higher in group B as compared with group A ( 6.1 vs. 3.6 % respectively , P = 0.006 ) . There was no difference in the rate of preterm delivery between the two groups . CONCLUSIONS The increased incidence of pregnancy loss in pregnant women with TSH levels between 2.5 and 5.0 mIU/liter provides strong physiological evidence to support redefining the TSH upper limit of normal in the first trimester to 2.5 mIU/liter
Controlled trials on infant neurodevelopment were lacking ; gestational iodine supplementation reduced maternal thyroid volume and serum thyroglobulin and in some studies prevented a rise in serum thyroid-stimulating hormone .
Iodine supplementation improves some maternal thyroid indices and may benefit aspects of cognitive function in school-age children , even in marginally iodine-deficient areas .
BACKGROUND Although the detrimental effects of severe iodine deficiency are well recognised , the benefits of correcting mild-to-moderate iodine deficiency are uncertain .
OBJECTIVES We undertook a systematic review of the impact of iodine supplementation in population s with mild-to-moderate iodine deficiency .