By Kenneth L. Noller, MD
The American College of Obstetricians and Gynecologists
The thyroid is a small gland in the neck that produces hormones that regulate metabolism, heart rate, body temperature, blood pressure, weight, and energy level. When the thyroid is not functioning properly, producing too little or too much hormone, it can wreak havoc on all the organs in the body.
Thyroid disease affects 1% to 4% of women in the US, but it may be initially overlooked because its symptoms often develop slowly or seem to be related to lifestyle or other health problems.
Hypothyroidism develops when there is not enough thyroid hormone being released into the body. It is usually caused by an inflammation of the thyroid gland but can also be caused by taking too much medication to control an overactive thyroid or by a low-iodine diet.
Symptoms of hypothyroidism can include fatigue, decreased appetite, changes in menstrual periods, loss of sex drive, constipation, muscle cramps, brittle nails, and hair loss. It can be treated with medication that slowly raises the level of thyroid hormone in the blood. Most people with hypothyroidism must take medication for the rest of their lives and have their blood checked regularly.
Hyperthyroidism, or an overactive thyroid gland, is most common in women ages 20 to 40 and is frequently caused by a disorder called Graves’ disease. It can also develop when too much medication is taken to control an underactive thyroid.
Women with hyperthyroidism may experience fatigue, weight loss, nervousness, rapid heart beat, increased sweating, heat intolerance, changes in menstrual periods, more frequent bowel movements, and tremors. Antithyroid medication may be prescribed to reduce the amount of thyroid hormone in the body. Medication to control rapid heart beat may also be recommended.
Uncontrolled thyroid disease during pregnancy can lead to preeclampsia (high blood pressure during pregnancy), irregular heartbeat, heart failure, early separation of the placenta, and birth defects. Fortunately, when thyroid disease is well controlled, most women can have healthy babies.
Some women who had normal thyroid function during pregnancy may experience postpartum thyroiditis, which is typically a short-term condition.
ACOG recommends thyroid testing for pregnant women who exhibit symptoms of thyroid disease or who have a personal history of thyroid disease. Women age 65 and older and women with a strong family history of thyroid or other autoimmune diseases, such as diabetes or rheumatoid arthritis, should also be screened.
For more information, the ACOG Patient Education Pamphlet “Thyroid Disease” is available in English and Spanish at www.acog.org/publications/patient_education.