• Congenital Hypothyroidism

    (Cretinism)

    Definition

    The thyroid is a gland in the lower neck. It makes hormones that regulate growth, brain development, and metabolism. Hypothyroidism is a low or absent production of these hormones. Congenital means the conditions is present since birth.
    The Thyroid Gland
    IMAGE
    Copyright © Nucleus Medical Media, Inc.
    If this condition is not treated it can cause damage to the brain. This can lead to intellectual disability and abnormal growth.

    Causes

    In most cases, the cause is unknown, but it is probably genetic. The most common known causes are abnormal development of the thyroid gland or a defect in producing thyroid hormone. About 15% of cases are inherited.
    Babies may have a temporary shortage in their thyroid hormones, which is more common if born before 40 weeks.

    Risk Factors

    Factors that may increase the chance of congenital hypothyroidism include:
    • Medication during pregnancy, such as radioactive iodine therapy
    • Maternal autoimmune disease
    • Too much iodine during pregnancy
    • Family history of congenital hypothyroidism

    Symptoms

    Symptoms or signs take time to develop. The symptoms of congenital hypothyroidism may include the following:
    • Puffy face
    • Coarse facial features
    • Dull look
    • Thick protruding tongue
    • Poor feeding
    • Choking episodes
    • Constipation or reduced stooling
    • Yellow skin color—jaundice
    • Short stature
    • Swollen abdomen
    • Decreased activity
    • Sleeps a lot
    • Rarely cries or hoarse cry
    • Dry brittle hair; low hairline
    • Poor muscle tone
    • Cool and pale skin
    • Poor weight gain due to poor appetite
    • Poor growth
    • Difficult breathing
    • Low temperature
    • Swollen hands, feet and genitals

    Diagnosis

    At birth, most infants are screened for this condition. Blood tests will be able to identify thyroid levels. Images of the thyroid may also be taken with:
    • Thyroid scan (technetium)
    • Nuclear imaging (scintigraphy)

    Treatment

    The outcome is best if the condition is caught early. It is important to start treatment before the brain and nervous system are fully developed. If treatment is given early, it could prevent damage. Left untreated, the condition can lead to poor mental development and delayed growth.
    Medication will treat the hypothyroidism. The medication will replace the missing hormone.
    Once medication starts, the levels of thyroid hormones are checked often. This will help to keep the values within normal range. If values are kept within a normal range, there are no side effects or complications.

    Prevention

    Most cases cannot be prevented. The following are some things the mother can do during pregnancy to reduce the risk:
    • Avoid radioactive iodine treatment or iodine as antiseptic during pregnancy
    • Consume enough, but not too much iodine during pregnancy

    RESOURCES

    American Thyroid Association http://www.thyroid.org

    Genetics Home Reference http://ghr.nlm.nih.gov

    CANADIAN RESOURCES

    Health Canada http://www.hc-sc.gc.ca

    Thyroid Foundation of Canada http://www.thyroid.ca

    References

    American Academy of Pediatrics, Rose SR, Section on Endocrinology and Committee on Genetics, et al. Update of newborn screening and therapy for congenital hypothyroidism. Pediatrics. 2006;117(6):2290-2303.

    Bongers-Schokking JJ, Koot HM, et al. Influence of timing and dose of thyroid hormone replacement on the development in infants with congenital hypothyroidism. J Ped. 2000;136(3):292-297.

    Castanet M, Polak M, Leger J. Familial forms of thyroid dysgenesis. Endocr Dev. 2007;10:15-28.

    Gruters A, Krude H, Biebermann H. Molecular genetic defects in congenital hypothyroidism. Europ J Endocr. 2004;151 Suppl 3:U39-U44.

    Congenital hypothyroidism. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated March 24, 2016. Accessed March 29, 2016.

    LeFranchi SH, Austin J. How should we be treating children with congenital hypothyroidism. J Pediatr Endocrinol Metab. 2007;20(5):559-578.

    Revision Information

  • LiveWell personal health survey

    How healthy are you really? Find out – free.Learn more

    It's time to stop guessing. If you want to make some changes but just aren't sure how, the free personal health survey from LiveWell is a great place to start.

  • HeartSHAPE Spotlight

    At risk for a heart attack? Learn more

    Fight heart disease and prevent heart attacks. HeartSHAPE® is a painless, non-invasive test that checks pictures of your heart for early-stage coronary disease.

  • Calories and Energy Needs

    Calorie NeedsLearn more

    How many calories do you need to eat each day to maintain your weight and fuel your physical activity? Enter a few of your stats into this calculator to find out.

  • Ideal Body Weight

    Ideal Body WeightLearn more

    Using body mass index as a reference, this calculator determines your ideal body weight range. All you need to do is enter your height.

  • Body Mass Index

    Body Mass IndexLearn more

    This tool considers your height and weight to assess your weight status.


  • Can we help answer your questions?

    Wellmont Nurse Connection is your resource for valuable health information any time, 24 hours a day, seven days a week. Speak to a Nurse any time, day or night, at (423) 723-6877 or toll-free at 1-877-230-NURSE.