Congenital Hypothyroidism

• ● Congenital hypothyroidism is a disorder related to absent or non-functioning thyroid gland upon birth which causes reduction of both T4 and T3 hormones.

  ● T4 is thyroxine and T3 is triiodothyronine. These hormones are responsible for controlling the rate of metabolism in the body. T4 is our major and primary thyroid hormone, T3 is more potent one formed from conversion of T4 to T3.

  ● This disorder occurs 1 in every 4000 live births and about twice in girls than in boys.
• ● Cause is usually unknown although if a pregnant woman has hyperthyroidism, this can cause the fetal thyroid to not fully develop because at this time, the fetus is bombarded by the many maternal thyroid hormones, so there is no use of the fetal thyroid hormones.

  ● There are other types of hypothyroidism

  1. Acquired

  2. Hashimoto’s Thyroiditis
• ASSESSMENT

  ● The condition may not be noticeable initially because the mother’s thyroid hormones may still be present at birth. Symptoms become apparent by about 3 to 6 months.

  1. Altered body proportion, short and thick neck, short stature, short legs

  2. Hypotonic muscles in extremities causing decreased deep tendon reflexes and in digestive tract causing chronic constipation

  3. Delayed dentition or teeth may be defective
• 4. Enlarged and protruding tongue causing respiratory difficulty, noisy respirations, or airway obstruction

  5. Hypothermia with cool extremities

  6. Dry, scaly skin which does not perspire

  7. Sleeps excessively

  ● All these findings mentioned here result because there is a slow metabolic rate from less thyroid hormones and because it causes progressive physical and cognitive challenges, early diagnosis of this disease is crucial. That’s why in the Philippines, this is a part of the newborn screening program.
• DIAGNOSTIC AND LABORATORY TESTS

  ● Low radioactive iodine uptake levels

  ○ Iodine is needed to combine tyrosine 4 and 3 to make

  T4 and T3 which we get from foods that we eat particularly seafood or iodized salt

  ● Low serum T4 and T3 levels

  ○ As evidence by the insufficiency of the thyroid gland to secrete these hormones
• ● Elevated thyroid-stimulating factor

  ○ Because the pituitary gland attempts to stimulate the thyroid gland to secrete hormones that’s its normal function

  ● Blood lipids are increased

  ○ Because of less metabolism due to less thyroid hormones

  ● Radiographs reveal delayed bone growth

  ○ As evidence of stunted growth.
• MANAGEMENT

  1. Oral administration of synthetic thyroid hormone, sodium levothyroxine.

  ● Small dose is given at first then gradually increase to therapeutic levels. This is taken indefinitely or for life to supplement what the thyroid cannot make.

  2. While on thyroid hormone therapy, give supplemental vitamin D to prevent rickets.

  ● Rickets is a skeletal disorder caused by lack of vitamin D, calcium or phosphate. - This is important to give especially when rapid bone growth begins.