According to Health Day News:
Screening and treating expectant moms for thyroid problems at the end of the first trimester doesn't improve children's IQs at age 3, a new study finds.
Thyroid hormones are crucial for the development of a baby's brain and nervous system, and until the middle of the second trimester, those hormones come from the mother. Since a malfunctioning thyroid in the mother has been associated with mental impairments in her child, researchers reasoned that if they screened for maternal thyroid disease in pregnancy and treated any problems found, they might be able to improve function in the offspring. Treatment includes supplementary thyroid hormone medications such as levothyroxine.
However, this large study found that the intervention did not seem to help. READ MORE