Background Subclinical @entity1374 during pregnancy may be associated with adverse outcomes, including a lower-than-normal IQ in offspring. It is unknown whether @entity1955 treatment of @entity1 who are identified as having @entity1375 or hypothyroxinemia during pregnancy improves cognitive function in their @entity1 . Methods We screened @entity1 with a singleton pregnancy before 20 weeks of gestation for @entity1375 , defined as a thyrotropin level of 4.00 mU or more per liter and a normal free @entity1955 (T4) level (0.86 to 1.90 ng per deciliter [11 to 24 pmol per liter]), and for hypothyroxinemia, defined as a normal thyrotropin level (0.08 to 3.99 mU per liter) and a low free T4 level (<0.86 ng per deciliter). In separate trials for the two conditions, @entity1 were randomly assigned to receive @entity1955 or placebo. Thyroid function was assessed monthly, and the @entity1955 dose was adjusted to attain a normal thyrotropin or free T4 level (depending on the trial), with sham adjustments for placebo. @entity1 underwent annual developmental and behavioral testing for 5 years. The primary outcome was the IQ score at 5 years of age (or at 3 years of age if the 5-year examination was missing) or @entity204 at an age of less than 3 years. Results A total of 677 @entity1 with @entity1375 underwent randomization at a mean of 16.7 weeks of gestation, and 526 with hypothyroxinemia at a mean of 17.8 weeks of gestation. In the @entity1375 trial, the median IQ score of the @entity1 was 97 (95% confidence interval [CI], 94 to 99) in the @entity1955 group and 94 (95% CI, 92 to 96) in the placebo group (P=0.71). In the hypothyroxinemia trial, the median IQ score was 94 (95% CI, 91 to 95) in the @entity1955 group and 91 (95% CI, 89 to 93) in the placebo group (P=0.30). In each trial, IQ scores were missing for 4% of the @entity1 . There were no significant between-group differences in either trial in any other neurocognitive or pregnancy outcomes or in the incidence of adverse events, which was low in both groups. Conclusions Treatment for @entity1375 or hypothyroxinemia beginning between 8 and 20 weeks of gestation did not result in significantly better cognitive outcomes in @entity1 through 5 years of age than no treatment for those conditions. (Funded by the Eunice Kennedy Shriver National Institute of @entity1 Health and @entity1 Development and the National Institute of @entity16 and @entity64 ; ClinicalTrials.gov number, NCT00388297 .).

Treatment of XXXX or Hypothyroxinemia in Pregnancy.

@entity1 :: ('9606', 'Species') :: ['Child', 'children', 'women', 'Children', 'Human'] @entity1375 :: ('MESH:D007037', 'Disease') :: ['subclinical hypothyroidism'] @entity64 :: ('MESH:D020521', 'Disease') :: ['Stroke'] @entity16 :: ('MESH:D009422', 'Disease') :: ['Neurological Disorders'] @entity1955 :: ('MESH:D013974', 'Chemical') :: ['thyroxine', 'levothyroxine'] @entity204 :: ('MESH:D003643', 'Disease') :: ['death'] @entity1374 :: ('MESH:D013959', 'Disease') :: ['thyroid disease']
@entity1375 :: (MESH:D007037,Disease) :: ['Subclinical Hypothyroidism']
