What is the affects of high thyroid on a fetus in early pregnacy.

Depends: The answer depends on how high the thyroid hormone is and what the cause is (nodule or thyroiditis). In general as long as the thyroid function is restored/ returned to normal or near normal, there should not be significant effects. Talk to your doctor to review your specific situation.

Infant hyperthyroid: Hyperthyroidism during pregnancy raises small risk , approximately 1% to 2%, that infant will develop hyperthyroidism before birth , condition known as fetal thyrotoxicosis or known as neonatal hyperthyroidism. Rarely hyperthyroidism can also occur in the newborns of mothers who have history of graves' disease, treated medically or by ablation. Autoimmune with antibodies crossing the placenta.