Thyroid disease is common in women of childbearing age and can have significant effects on the development of the fetus and perinatal outcomes. Maternal thyroid hormone is critical for proper fetal neurodevelopment and the fetus relies on thyroid hormone from it’s mother for the first half of pregnancy. Both overt maternal hypothyroidism and overt maternal hyperthyroidism have been shown to be associated with adverse effects on central nervous system grey matter and neurocognitive development of offspring as well as increased obstetrical risks. Treatment of overt thyroid conditions improves outcomes. Subclinical maternal hypothyroidism may increase adverse neurocognitive and obstetrical outcomes although data is conflicting. To date, treatment of subclinical hypothyroidism has not shown benefit. Subclinical hyperthyroidism is well tolerated in pregnancy. Thyroid autoantibodies alone may also affect neurodevelopment and obstetrical outcomes however recent data has shown no improvement with levothyroxine treatment. Several rare maternal genetic thyroid conditions can affect the fetus including a TSH receptor mutation leading to hypersensitivity to hCG and thyroid hormone resistance. The thyroid plays a crucial role in fetal health and understanding it is important for optimal care. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.

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