- What is the thyroid gland?
The thyroid gland is a butterfly-shaped endocrine gland that is normally located in the lower front of the neck. The thyroid’s job is to make thyroid hormones, which are secreted into the blood and then carried to every tissue in the body.
Thyroid hormone helps the body use energy, stay warm and keep the brain, heart, muscles, and other organs working as they should.
- What are the normal changes in thyroid function associated with pregnancy?
The thyroid gland can increase in size during pregnancy called goiter especially in iodine-deficient areas of the world like India.
- What is the interaction between the thyroid function of the mother and the baby?
For the first 10-12 weeks of pregnancy, the baby is completely dependent on the mother for the production of thyroid hormone most crucial time of development. The World Health Organization recommends iodine intake of 200 micrograms/day during pregnancy to maintain adequate thyroid hormone production. What are the risks of hypothyroidism to the mother? Untreated, or inadequately treated, hypothyroidism has been associated with maternal anemia (low red blood cell count),muscle pain, weakness, heart failure, high blood pressure, placental abnormalities, low birth weight infants , heavy bleeding after delivery
- What are the risks of maternal hypothyroidism to the baby?
Thyroid hormone is critical for brain development in the baby. Children born with hypothyroidism (no thyroid function at birth) can have severe cognitive, neurological and developmental abnormalities if the condition is not recognized and treated promptly. These developmental abnormalities can largely be prevented if the disease is recognized and treated immediately after birth.It is vital to check a woman’s TSH value either before becoming pregnant (pre-pregnancy counseling) or as soon as pregnancy is confirmed. This is especially true in women at high risk for thyroid disease, such as those with prior treatment for hyperthyroidism, a positive family history of thyroid disease and those with a goiter.
Clearly, woman with established hypothyroidism should have a TSH test once pregnancy is confirmed, as thyroid hormone requirements increase during pregnancy, often leading to the need to increase the levothyroxine dose. If the TSH is normal, no further monitoring is typically required. Its better to discuss with your doctor.
- How should a woman with hypothyroidism be treated during pregnancy?
The treatment of hypothyroidism in a pregnant woman is adequate replacement of thyroid hormone in the form of thyroxine tablets.
It is important to note that thyroxine requirements frequently increase during pregnancy, often times by 25 to 50 percent. Ideally, hypothyroid women should have their levothyroxine dose optimized prior to becoming pregnant. Women with known hypothyroidism should have their thyroid function tested as soon as pregnancy is detected and their dose adjusted by their physician as needed to maintain a TSH in the normal range.
Thyroid function tests should be checked approximately every 6-8 weeks during pregnancy to ensure that the woman has normal thyroid function throughout pregnancy.
It is also important to recognize that iron and calcium taken during pregnancy can impair the absorption of thyroid hormone from the gastrointestinal tract. Consequently, levothyroxine and prenatal vitamins should not be taken at the same time In many hospitals newborn screening for thyroid disorders is being done as a routine after first few days of birth to prevent hypothyroidism related developmental delay.