Congenital Hypothyroidism

Guidance for primary care clinicians receiving a positive newborn screen result

Other Names

CH
Congenital myxedema
Neonatal hypothyroidism
Primary congenital hypothyroidism

ICD-10 Coding

E03.1, Congenital hypothyroidism without goiter
P09.2, Abnormal findings on neonatal screening for congenital endocrine disease

Disorder Category

Endocrine disorder

Screening

Abnormal Finding

Elevated thyroid stimulating hormone (TSH), low free thyroxine (T4)

Tested By

Congenital hypothyroidism is tested by TSH and/or T4 hormone levels from whole dried blood spots. Newborn screening for congenital hypothyroidism is performed nationally in the United States, although the timing of screening and hormone levels tested vary by state.
False-negative screens can occur with a delayed TSH surge, seen more commonly in newborns with low birth weight, prematurity, and clinical illness. Therefore, infants with clinical suspicion of congenital hypothyroidism should be tested regardless of their newborn screen results.

Description

Congenital hypothyroidism is caused by an underactive thyroid gland. Thyroid hormones are essential for metabolism, growth, temperature regulation, and brain development. Approximately 85% of cases are due to an absent, hypoplastic, or improperly positioned thyroid gland, also called thyroid dysgenesis or agenesis. Other causes include thyroid hormone dyshormonogenesis, in which there is a defect in thyroid hormone biosynthesis; TSH receptor resistance; or, less commonly, disruption of the hypothalamic-pituitary-thyroid axis, also known as central hypothyroidism. Rarely, congenital hypothyroidism may occur as part of a syndrome, including Pendred syndrome, Bamforth-Lazarus syndrome, and brain-lung-thyroid syndrome. With early detection and prompt initiation of treatment, most affected individuals will have normal growth and development.

Clinical Characteristics

Most newborns with congenital hypothyroidism are asymptomatic at birth. If findings are present, they may include:
  • Poor feeding
  • Excessive sleepiness
  • Constipation
The following findings may be seen on examination but typically are not present at birth:
  • Puffy face (myxedematous appearance)
  • Large fontanelles
  • Macroglossia
  • Umbilical hernia
  • Jaundice
  • Decreased strength
With treatment initiated promptly, typically life-long thyroid hormone replacement therapy, most affected individuals will have normal growth and development.
Without treatment, affected individuals will develop:
  • Significant developmental delay
  • Poor growth (height and weight)
  • Physical exam findings as noted above

Incidence

Primary congenital hypothyroidism occurs in 1 in every 2,000 to 4,000 births in the United States. [Hinton: 2010] Central congenital hypothyroidism is much less common and occurs in 1; 16,000 births worldwide. [van: 2021] Almost twice as many female newborns are affected as male newborns. [Hinton: 2010] [Danner: 2022]

Inheritance

Most incidences of congenital hypothyroidism are due to sporadic defects in thyroid development, occurring in newborns with no family history. However, ~15% of cases can be linked to underlying gene mutations. When inherited, congenital hypothyroidism typically has an autosomal recessive inheritance pattern. [Segni: 2000] A family history of congenital hypothyroidism, associated cardiac, kidney, or midline malformations, lung disorders, deafness, neurological signs (i.e., choreoathetosis, hypotonia), and any sign of Albright hereditary osteodystrophy, suggest a possible genetic etiology. [Segni: 2000] Although much less common than primary hypothyroidism, central congenital hypothyroidism is frequently associated with X-linked genes. [Cherella: 2020]

Primary Care Management

Next Steps After a Positive Screen

  • Contact the family to ensure they are aware of the abnormal screening result, provide support, and answer additional questions. In many instances, the state’s newborn screening program may have already contacted the family.
  • Perform a clinical evaluation to assess for associated complications and treat as indicated.
    • Complications may include jaundice, poor feeding, and constipation.
    • Evaluation should include an exam to look for features suggestive of an underlying syndromic cause.
  • Arrange prompt confirmatory testing.
    • Note: false-positive screens may occur with a normal postnatal TSH surge or transient increase in TSH from exposure to maternal anti-thyroid medications.
  • See the ACT Sheet for Elevated TSH (ACMG) (PDF Document 349 KB) or the ACT Sheet for Low T4 and/or Elevated TSH (ACMG) (PDF Document 348 KB) for additional information.

Confirming the Diagnosis

To confirm the diagnosis of congenital hypothyroidism, work with Newborn Screening Services (see OH providers [1]) to determine the next steps.
  • If a second screen is routine in your state, ensuring it is performed in a timely manner may be sufficient for diagnosis.
  • If the TSH flags as critical, confirmatory testing should be sent immediately.
    • Confirmatory testing for congenital hypothyroidism should include serum-free T4 and TSH levels. Diagnosis is confirmed with the following results: Low free T4, high TSH. Other confirmatory tests may include a reduced total T4.
    • A low free T4 with a reduced or inappropriately normal TSH is consistent with central congenital hypothyroidism. Report findings to the newborn screening program.

If the Diagnosis is Confirmed

For evaluation and ongoing collaborative management, consult Pediatric Endocrinology (see OH providers [1]).
  • Medication management should be initiated promptly. Levothyroxine should be started and adjusted in collaboration with a pediatric endocrinologist.
    • The typical starting dose is 10-15 µ/kg/day.
    • Liquid formulations are not stable and should not be used. The family should be instructed to dissolve a tablet and administer it in 10 ml of water or formula at the beginning of a feeding.
  • Educate the family on the diagnosis, treatment, and outcomes.
    • Use of visuals or handouts may be helpful.
    • Provide the family with further resources to provide information and support. See “For patient and family” resources below.
    • Educate the family that hormone replacement therapy prevents developmental delay and poor growth.
  • Thyroid function monitoring with TSH and free T4 testing are recommended at routine intervals in the first 3 years of life as doses can frequently change during this time.
  • Levels are frequently checked:
    • At 2 and 4 weeks after initiation of therapy
    • Every 1 to 2 months during the first 6 months of life
    • Every 3 to 4 months between 6 months and 3 years
    • Every 6 to 12 months until growth is completed
    • At more frequent intervals when dose changes occur, abnormal values are obtained, and when compliance is questioned
  • Monitor cognitive development of the child. If indicated, refer to Early Intervention for Children with Disabilities/Delays (see OH providers [3]) and/or Developmental - Behavioral Pediatrics (see OH providers [1]). However, with early detection and prompt initiation of treatment, most affected individuals will have normal growth and development.
  • Monitor growth of the child. However, growth rate and adult height are normal if thyroid hormone treatment is consistently maintained.
  • Be aware that, while uncommon, babies with congenital hypothyroidism have an increased risk of cardiac anomalies, including atrial and ventricular septal defects, and renal and urinary tract anomalies. [Segni: 2000]

Resources

Information & Support

For Professionals

Congenital Hypothyroidism (OMIM)
Information about clinical features, diagnosis, management, and molecular and population genetics; Online Mendelian Inheritance in Man, authored and edited at the McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine

Communicating Newborn Screening Results to Families (ACHDNC) (PDF Document 289 KB)
One-page guide to help clinicians effectively communicate positive newborn screening results to parents; Advisory Committee on Heritable Disorders in Newborns and Children.

For Parents and Patients

Congenital Hypothyroidism (The Magic Foundation)
Information about congenital hypothyroidism from The Magic Foundation, a nonprofit organization, providing support services for families of children with a wide variety of chronic and/or critical disorders, syndromes, and diseases that affect growth. Offers patient assistance programs.

Congenital Hypothyroidism FAQs
Answers to frequently asked questions about congenital hypothyroidism. Links to other information about pediatric and adult thyroid conditions, tests, and treatments; American Thyroid Association.

Congenital Hypothyroidism (MedlinePlus)
Information for families that includes description, frequency, causes, inheritance, other names, and additional resources; from the National Library of Medicine.

Congenital Hypothyroidism (KidsHealth)
Concise, easy-to-read web information with an illustration of the thyroid gland. The information is available to print, listen, or read. Also available in Spanish.

Pediatric Endocrine Society Patient Resources
A Patient Education Subcommittee comprising members from the PES Education Council and the American Academy of Pediatrics Section on Endocrinology have developed a series of patient education fact sheets covering topics such as growth, thyroid, puberty, diabetes, adrenal, PCOS, and vitamin D.

How Newborn Screening Changed My Family's Life: Congenital Hypothyroidism
Short article about one family's experience having their son diagnosed with congenital hypothyroidism by newborn screening.

Patient Education

Congenital Hypothyroidism Patient Education (PDF Document 442 KB)
2-page printable PDF answering frequently asked questions about congenital hypothyroidism; American Thyroid Association.

Hipotiroidismo Congénito (PDF Document 440 KB)
EN ESPANOL/Spanish 3-page printable PDF answering frequently asked questions about congenital hypothyroidism; American Thyroid Association.

Tools

ACT Sheet for Elevated TSH (ACMG) (PDF Document 349 KB)
Contains short-term recommendations for clinical follow-up of the newborn who has screened positive; American College of Medical Genetics.

ACT Sheet for Low T4 and/or Elevated TSH (ACMG) (PDF Document 348 KB)
Contains short-term recommendations for clinical follow-up of the newborn who has screened positive; American College of Medical Genetics.

Confirmatory Algorithms for Congenital Hypothyroidism (T4) (ACMG) (PDF Document 213 KB)
An algorithm of the basic steps involved in determining the final diagnosis of an infant with a positive newborn screen; American College of Medical Genetics.

Confirmatory Algorithms for Congenital Hypothyroidism (TSH) (ACMG) (PDF Document 247 KB)
An algorithm of the basic steps for determining the final diagnosis of an infant with a positive newborn screen; American College of Medical Genetics.

Services for Patients & Families in Ohio (OH)

For services not listed above, browse our Services categories or search our database.

* number of provider listings may vary by how states categorize services, whether providers are listed by organization or individual, how services are organized in the state, and other factors; Nationwide (NW) providers are generally limited to web-based services, provider locator services, and organizations that serve children from across the nation.

Studies

Clinical Trials in Congenital Hypothyroidism (clinicaltrials.gov)
Studies looking at better understanding, diagnosing, and treating this condition; from the National Library of Medicine.

Helpful Articles

PubMed search for congenital hypothyroidism in children, last 2 years.

Segni M.
Congenital Hypothyroidism.
EndoText. 2000. PubMed abstract
A chapter from the indexed e-book, EndoText, this article provides detailed information on the pathophysiology, genetics, screening, treatment, and prognosis of congenital hypothyroidism.

Leung AKC, Leung AAC.
Evaluation and management of the child with hypothyroidism.
World J Pediatr. 2019;15(2):124-134. PubMed abstract
Useful review article on evaluation and treatment of pediatric hypothyroidism, by Canadian authors.

van Trotsenburg P, Stoupa A, Léger J, Rohrer T, Peters C, Fugazzola L, Cassio A, Heinrichs C, Beauloye V, Pohlenz J, Rodien P, Coutant R, Szinnai G, Murray P, Bartés B, Luton D, Salerno M, de Sanctis L, Vigone M, Krude H, Persani L, Polak M.
Congenital Hypothyroidism: A 2020-2021 Consensus Guidelines Update-An ENDO-European Reference Network Initiative Endorsed by the European Society for Pediatric Endocrinology and the European Society for Endocrinology.
Thyroid. 2021;31(3):387-419. PubMed abstract / Full Text
A European practice guideline endorsed by the European Society for Pediatric Endocrinology and the European Society for Endocrinology. Recommendations include the various neonatal screening approaches for CH as well as the etiology (also genetics), diagnostics, treatment, and prognosis of both primary and central CH.

Authors & Reviewers

Initial publication: March 2007; last update/revision: September 2022
Current Authors and Reviewers:
Author: Meghan M. O'Connor, MD
Contributing Author: Jennifer Goldman, MD, MRP, FAAP
Reviewer: Zoe Raleigh, MD
Authoring history
2018: update: Zoe Raleigh, MDA; Mary A. Murray, MDSA
2007: first version: Nicola Longo, MD, Ph.D.A
AAuthor; CAContributing Author; SASenior Author; RReviewer

Page Bibliography

Cherella CE, Wassner AJ.
Update on congenital hypothyroidism.
Curr Opin Endocrinol Diabetes Obes. 2020;27(1):63-69. PubMed abstract
The review summarizes recent advances in the diagnosis and management of patients with congenital hypothyroidism.

Danner E, Niuro L, Huopio H, Niinikoski H, Viikari L, Kero J, Jääskeläinen J.
Incidence of primary congenital hypothyroidism over 24 years in Finland.
Pediatr Res. 2022. PubMed abstract

Hinton CF, Harris KB, Borgfeld L, Drummond-Borg M, Eaton R, Lorey F, Therrell BL, Wallace J, Pass KA.
Trends in incidence rates of congenital hypothyroidism related to select demographic factors: data from the United States, California, Massachusetts, New York, and Texas.
Pediatrics. 2010;125 Suppl 2:S37-47. PubMed abstract

Segni M.
Congenital Hypothyroidism.
EndoText. 2000. PubMed abstract
A chapter from the indexed e-book, EndoText, this article provides detailed information on the pathophysiology, genetics, screening, treatment, and prognosis of congenital hypothyroidism.

van Trotsenburg P, Stoupa A, Léger J, Rohrer T, Peters C, Fugazzola L, Cassio A, Heinrichs C, Beauloye V, Pohlenz J, Rodien P, Coutant R, Szinnai G, Murray P, Bartés B, Luton D, Salerno M, de Sanctis L, Vigone M, Krude H, Persani L, Polak M.
Congenital Hypothyroidism: A 2020-2021 Consensus Guidelines Update-An ENDO-European Reference Network Initiative Endorsed by the European Society for Pediatric Endocrinology and the European Society for Endocrinology.
Thyroid. 2021;31(3):387-419. PubMed abstract / Full Text
A European practice guideline endorsed by the European Society for Pediatric Endocrinology and the European Society for Endocrinology. Recommendations include the various neonatal screening approaches for CH as well as the etiology (also genetics), diagnostics, treatment, and prognosis of both primary and central CH.