congenital Hypothyroidism - PowerPoint PPT Presentation

1 / 20
About This Presentation
Title:

congenital Hypothyroidism

Description:

Title: congenital Hypothyroidism Last modified by: Anoop Agrawal User Document presentation format: Custom Other titles: Palatino ProN W3 Arial ... – PowerPoint PPT presentation

Number of Views:1456
Avg rating:3.0/5.0
Slides: 21
Provided by: bcm85
Category:

less

Transcript and Presenter's Notes

Title: congenital Hypothyroidism


1
congenital Hypothyroidism
  • Baylor College of Medicine
  • Anoop Agrawal, M.D.

2
Case study- C.V.
  • C.V. is a FT, 4kg, 7 day old hispanic infant
    girl, born to a 22 yo female, NSVD, GBS negative,
    APGARS 9/9. You receive a call from the Texas
    Department of Health stating C.V. has an abnormal
    thyroid study on her newborn screen.
  • What is your course of action?

3
(No Transcript)
4
Background
  • Thyroid development begins around 17th day of
    gestation.
  • Hypothalamus releases TRH by 20th week of
    gestation. T3 levels remain relatively low until
    the 30th week.
  • Fetus is protected by increased activity of
    deiodinase enzymes in the brain and maternal
    thyroid hormone transfer across the placenta.
  • Placenta is impermeable to TSH.

5
incidence
  • In US - 1 3,500 live births
  • Females to Males - 21 ratio
  • Hispanic - 12000, White infants - 14000,
    African American - 132,000
  • Children with Down syndrome have 35 fold increase
    risk.
  • Congenital Hypothyroidism is the most common
    treatable cause of mental retardation.

6
etiology of C.H.
  • What are the causes that result in lifelong
    hypothyroidism?
  • Thyroid Dysplasia (agenesis, hypoplasia, or
    ectopy) - incidence is sporadic in 85 of cases
  • Dyshormonogenesis - inborn error of thyroxine
    synthesis - 10 of cases
  • Secondary or Central Hypothyroidism (125,000 -
    100,000)

7
Etiology of C.H.
  • What are the causes of transient hypothyroidism?
  • Maternal or neonatal drug exposure
  • Iodine deficiency (in Europe 1100 vs. in US
    150,000 due iodized salt in foods)
  • Maternal antibodies - this form resolves in 1 to
    3 months as antibodies are cleared
  • Gestational hyperthyroidism

8
(No Transcript)
9
Clinical manifestations
  • macroglossia
  • large fontanelles
  • hypotonia
  • umbilical hernia
  • prolonged unconjugated hyperbilirubinemia
  • hoarse cry

10
Clinical Findings Finffmanifestations
  • 95 of newborn will have no evidence of disease
  • Can be associated with other congenital
    malformations - mainly cardiac
  • renal and urologic deformities also seen

11
Newborn screening
  • All states screen for hypothyroidism - type of
    testing is variable T4 with TSH backup vs. TSH
    alone
  • 4 million infants are screened annually in US, of
    which 1,600 will be diagnosed with congenital
    hypothyroidism

12
Evaluation
13
case - c.v.
  • State TSH screen reported to be gt400.
  • C.V. was called into the office the next day.
    Thyroid function tests were performed via
    venipuncture.
  • TSH gt 54, free T4 - QNS, thyroglobulin lt1
  • Started on thyroxine 10 mcg/kg/day - or 40 mcg
    per day. Referred to Endocrine Clinic.

14
Treatment
  • Start at 10-15 mcg/kg/day as single daily dose.
  • Initiation of hormone replacement with
    l-thyroxine can wait until diagnostic labs
    completed.
  • Certain milks and drugs can interfere with
    thyroxine absorption soy formulas, iron,
    calcium, sucralfate, aluminum hydroxide, bile
    acid sequestrants.

15
Treatment
  • How should thyroxine be administered to the
    infant?
  • It is available only as a tablet
  • DO NOT HAVE THE PHARMACY COMPOUND THE TABLET INTO
    A SOLUTION.
  • Tablet should be crushed and given in a small
    amount of milk or water.

16
Permanent vs. transient
  • How do you determine if child has permanent vs.
    transient hypothyroidism?
  • After 3 years of age, discontinue therapy for 30
    days. If low free T4 and high TSH are found,
    then permanent is confirmed.
  • Thyroid scan or u/s - uncommonly performed.
  • If TSH rises above 20 mU/L after the first year
    of life in setting of insufficient T4 therapy,
    then likely to be permanent.

17
Follow-up care
  • AAP recommends the following schedule
  • at 2 and 4 weeks after initiation of T4 treatment
  • every 1 to 2 months during first 6 mos.
  • every 3 to 4 months between 6 mos and 3yrs
  • every 6 to 12 months thereafter until growth is
    complete
  • 2 weeks after any change in dose

18
Follow up care
  • Serum T4 concentration should become normal
    within 1-2 weeks of treatment.
  • Serum TSH should be normal within 1 month of
    treatment.

19
Pedi endocrine
  • In HCHD, pediatric endocrinologist available at
    Casa de Amigos
  • no outpatient pedi endo at BTGH
  • Depending on the type of Medicaid, a child may be
    referred to either Casa de Amigos or Texas
    Childrens.

20
conclusion
  • Congenital hypothyroidism is seen most commonly
    in females, hispanics.
  • Thyroid dysgenesis is most common cause in the
    US.
  • Iodine deficiency in the maternal diet is 1
    cause worldwide.
  • Initiation with hormone replacement should not be
    delayed.
  • Overall, long term outcomes are good.
Write a Comment
User Comments (0)
About PowerShow.com