Hypothyroidism During Pregnancy Part I
Thyroid disease is particularly common in women of child-bearing age. As a result, it is no surprise that thyroid disease may complicate the course of pregnancy. It is estimated that 2.5% of all pregnant women have some degree of hypothyroidism. The frequency varies among different populations and different countries. While pregnancy itself is a natural state, and by no means should be considered a "disease," thyroid disorders during pregnancy may affect both mother and baby. This article focuses specifically on hypothyroidism and pregnancy. After a general description of normal and abnormal thyroid function, recent data on long term consequences in children of mothers who had hypothyroidism during pregnancy will be reviewed.
What is the thyroid gland?
The thyroid is a gland weighing about 15 grams (about half an ounce) that is located in the front of the neck just below the Adam's apple (cricoid cartilage). The thyroid gland is responsible for the production of the body's thyroid hormone. The thyroid responds to hormonal signals from the brain to maintain a constant level of thyroid hormone. The hormone signals are sent by specialized areas of the brain (hypothalamus and pituitary), eventually sending thyroid stimulating hormone (TSH) that promotes thyroid hormone production by the thyroid gland.see picture below
What happens with thyroid disease?
Disease of the thyroid gland is extremely common. In some conditions, the thyroid may produce too much hormone. In other conditions, the thyroid may be damaged or destroyed and little, if any, thyroid hormone is produced. The main thyroid hormone is called thyroxine, or T4.
Symptoms vary depending on whether there is too much or too little T4 in the blood. With an excess of T4 (hyperthyroidism), patients complain of feeling restless, emotionally hyper, and hot and sweaty. They may have tremors, trouble concentrating, and weight loss. Frequent bowel movements and diarrhea are common.
If T4 levels are low (hypothyroidism) as a result of decreased production by the thyroid gland, patients often notice fatigue, lethargy, and weight gain. Constipation is common and many patients with hypothyroidism report feeling excessively cold. Part II soon