Congenital hypothyroidism (CH) is a condition found in newborn babies when the thyroid gland does not produce enough thyroid hormone. You can find more information about the causes of congenital hypothyroidism in the CH overview article. Unless treatment begins soon after birth, babies born with CH experience reduced intelligence, abnormal growth, and possible neurological defects.
There are two basic types of congenital hypothyroidism known as permanent and transient.
• Permanent congenital hypothyroidism - This condition is usually the result of a missing or abnormal thyroid that cannot produce enough thyroid hormone. Infants born with this type of hypothyroidism will need life-long treatment.
• Transient congenital hypothyroidism – Approximately 10 to 20 percent of infants born with hypothyroidism have this temporary form of the disease. In most cases, the cause is iodine deficiency due to the mother not having enough iodine in her diet. Adding iodine to the baby’s diet can reverse this type of hypothyroidism.
Women who have autoimmune thyroid disease can transfer antibodies to the unborn baby that prevents the baby’s thyroid from functioning correctly. This condition usually corrects itself within three months after birth as the mother’s antibodies are naturally cleared from the baby. Babies exposed to very high doses of iodine due to medications their mothers take while pregnant may also experience temporary malfunction of the thyroid that will resolve over time.
Infants with congenital hypothyroidism are often noted as being “good babies” because they do not cry as much as other infants and sleep most of the time.
Other symptoms of CH include:
• High birth weight
• Large head size
• Lower activity level, slow movements
• Feeding problems
• Poor growth or small size
• Jaundice (yellow coloration in the skin and whites of the eyes)
• Constipation or less stool
• Hoarse cry
• Dull expression
• Puffy face
• Thick or enlarged tongue that sticks out of the mouth
Children who have other congenital issues such as heart conditions or Down syndrome are more likely to also have CH. Infants with mild congenital hypothyroidism may show few symptoms at birth. Over time, symptoms become more obvious if the condition is left untreated.
Screening for this condition is routine in all 50 states in the United States as well as in Canada, Europe, Israel, Japan, Australia, and New Zealand. Other countries have testing programs in development. The test can be performed using blood from a heel prick. In the United States, approximately 4 million infants are screened each year and 1000 are diagnosed with CH. Worldwide, approximately 12 million infants are tested annually and 3000 are found to have the condition. (about.com)
Early diagnosis of congenital hypothyroidism is critical. Early diagnosis and early treatment can completely resolve all issues caused by the condition for most patients. Treatment for CH is thyroid hormone replacement. One study recommends diagnosis before age 13 days and obtaining a balance of thyroid hormone levels by age 3 weeks.
Parents should be aware that soy-based formulas can affect the absorption of thyroid hormone replacements. Consult with your child’s pediatrician or specialist before changing from milk to soy-based formula. Babies may need more thyroid hormone replacement with soy formula to maintain appropriate thyroid hormone levels.
Sources:
Medscape. Congenital Hypothyroidism. Daniel C. Postellon, MD. Web. December 14, 2011.
http://emedicine.medscape.com/article/919758-overview
Medline Plus. Neonatal hypothyroidism. Web. December 14, 2011.
http://www.nlm.nih.gov/medlineplus/ency/article/001193.htm
About.com: Thyroid Disease. Understanding and Diagnosing Congenital Hypothyroidism in Infants and Children. Mary Shomon. Web. December 14, 2011.
http://thyroid.about.com/cs/childrenseniors/a/hypothyroidkids.htm
PubMed Central. Congenital hypothyroidism. Maynika V. Rastogi and Stephen H. LaFranchi. Web. December 14, 2011.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2903524/
Genetics Home Reference. Congenital Hypothyroidism. Web. December 14, 2011.
http://ghr.nlm.nih.gov/condition/congenital-hypothyroidism
Reviewed December 15, 2011
by Michele Blacksberg RN
Edited by Jody Smith