Abstract
Thyroid dysfunction-changes in how well your thyroid gland works-can start during or after pregnancy in women who never had thyroid problems before. This occurs because pregnancy causes major changes in the levels of hormones made in the thyroid gland. When the thyroid makes too much of the thyroid hormones T3 and T4, it is called overactive thyroid or hyperthyroidism. This problem also causes very low levels of thyroid stimulating hormone (TSH), a hormone that tells the thyroid to make T3 and T4. An overactive thyroid greatly increases metabolism (how your body uses energy). It most often affects women ages 20 to 40, in their childbearing years. Hyperthyroidism during pregnancy is not common. However, the symptoms may be overlooked because some can mimic the hormonal changes a woman has in a normal pregnancy: for instance, feeling too warm, tired, or anxious. If left untreated, maternal hyperthyroidism poses a risk for both mother and baby. Pregnant women with uncontrolled hype rthyroidism can develop high blood pressure. There is also an increased risk of miscarriage, premature birth, and having a baby with a low birth weight.