Thyroid disease is a disorder that affects the thyroid's ability to produce the correct amount of several hormones that help regulate metabolism (how your body uses energy). Two pregnancy related hormones can cause your thyroid gland to over or under produce the correct amount of hormones.
What causes thyroid disease in pregnancy?
The thyroid is a gland located at the base of your neck. This gland controls functions in your body through two hormones T4 (Thyroxine) and T3 (triiodothyothyronine). Disorders of the thyroid occur when the gland makes too much (hyperthyroidism) or too little (hypothyroidism) hormone. Thyroid disease is more common in women than men. Often patients with thyroid disorders will require treatment and may even be diagnosed during pregnancy.
What are the symptoms of thyroid disease in pregnancy?
Symptoms of hypothyroidism may include fatigue, weakness, decreased appetite, feeling cold, hair loss, brittle nails, muscle aches and constipation. This condition is diagnosed through lab tests that reveal changes in hormone levels. Once diagnosed, hypothyroidism is treated with oral hormone replacement. Patients require close monitoring of hormone levels and medication doses. Most patients will require lifetime thyroid hormone replacement. Symptoms of hyperthyroidism include fatigue, weight loss, nervousness, rapid heartbeat, sweating, feeling hot, increase in bowel movement and tremors. Once diagnosed, this condition is treated with oral anti-thyroid medications. Patients may also require a medication to control their heart rate. Occasionally patients with hyperthyroidism will require removal of the gland through surgery or medication to destroy parts of the gland (high-dose radioactive iodine). These patients will then require thyroid hormone replacement.
How is thyroid disease in pregnancy diagnosed?
Simple blood tests that measure thyroid hormones (TSH, T3 and T4) can confirm whether you have hypothyroidism or hyperthyroidism.
What is the treatment for thyroid disease in pregnancy?
Fortunately these disorders can be safely treated in pregnancy. Thyroid replacement (for hypothyroidism) is safe to both the mother and unborn baby. Most anti-thyroid medications (for hyperthyroidism) are also safe in pregnancy. Your hormone levels will be closely monitored as they may change in pregnancy and your treatment will need to be changed. Radioactive-iodine treatment can cause harm to the baby's thyroid gland and cannot be used in pregnancy. With treatment, patients with thyroid disorders can have a healthy and safe pregnancy. Left untreated hypothyroidism during pregnancy can cause the unborn child to be smaller than other children at birth, have a lower IQ and be born at an earlier gestational age. Hypothyroidism in the mother can increase her risk of placenta abruption (when the placenta separates from the uterus prior to birth) and preeclampsia (a condition in pregnancy leading to high blood pressure and changes in kidney function). Untreated hyperthyroidism can also lead to early birth, babies being born smaller than normal, and the baby having hyperthyroidism that requires treatment. Untreated mothers are at risk for irregular heartbeats, heart failure and a disorder called thyroid storm, which can lead to rapid heart rate, confusion and coma.