Hypothyroidism%20During%20Pregnancy

1
Hypothyroidism During Pregnancy

• Rosa Carranza
• University of Texas Medical Branch at Galveston
• GNRS 5631 NNP1
• Debra Armentrout, RN, MSN, NNP-BC, PhD
• Leigh Ann Cates, MSN, RN, NNP-BC, RRT-NPS
• March 20, 2014

2
Objectives

• Review the pathophysiology of hypothyroidism
  during pregnancy
• Recognize the clinical manifestations of
  hypothyroidism in the newborn
• Discuss diagnostic evaluation of the neonate
• Discuss therapeutic options for maternal/fetal
  treatment
• Review evidence based guidelines for neonatal
  management
• Understand the economic, emotional, social
  implications for the family

3
PathophysiologyReview of normal thyroid
function

• Thyroid uses iodine to form components of T3 T4
• Low T3 T4 cause hypothalamus to release
  thyrotropin-releasing hormone (TRH)
• TRH stimulates pituitary to produce
  thyroid-stimulating hormone (TSH)
• TSH acts on thyroid to increase T3 T4
• Regulated by negative feedback
• (Blackburn, 2013)

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Pathophysiologypregnancy induced changes in
thyroid function

• Increased thyroid hormone iodine needs in
  pregnancy
• Estrogen Increases thyroid binding globulin
  (TBG) ? decreasing free thyroid hormones
• hCG Increases T3 T4 ? decreasing TSH (ratio of
  T3/T4 still less than TBG)
• Placenta increases enzymes that catabolize
  thyroid hormones
• Increased renal blood flow glomerular
  filtration? iodine loss
• (Blackburn, 2013)

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Impact on the fetus

• Fetus dependent on maternal T4 in 1st 10-12 weeks
  
• Thyroid hormones critical for brain development
• Contribute to maturation of retina, cochlea,
  lung, bones, thermogenesis
• Hypothyroidism can lead to cretinism - mental
  retardation stunted physical growth

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Clinical Manifestations

• Widely separated sutures
• Large fontanelles
• Short arms/legs
• Umbilical hernia
• Macroglossia
• Mental retardation
• Hypotonia
• Jaundice
• Poor feeding
• (National Library of Medicine, 2014)

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Diagnostic Evaluation of Newborn
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Treatment Options Maternal Hypothyroidism
Diagnosed Before Pregnancy

• Levothyroxine adjustment for TSH lt 2.5 mlU/L
• 30 Levothyroxine increase by 4-6 weeks of
  pregnancy
• Thyroid function test every 4-6 weeks
• Iodine 150 mcg/day before pregnancy
• Iodine 250 mcg/day during pregnancy
• (De Groot, Abalovich, Alexander, Amino, Barbour,
  Cobin, Eastman, Lazarus, Luton, Mandel, Mestman,
  Rovert, Sullivan, 2012).

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Treatment OptionsMaternal Hypothyroidism
Diagnosed During Pregnancy

• Identify high risk women by medical history
  exam
• Goal Normalize thyroid function ASAP
• Start Levothyroxine titrate dose for TSH lt 2.5
  mlU/L
• Thyroid function test every 4-6 weeks
• Iodine 250 mcg/day
• (De Groot, Abalovich, Alexander, Amino, Barbour,
  Cobin, Eastman, Lazarus, Luton, Mandel, Mestman,
  Rovert, Sullivan, 2012).

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Management of the Neonate

• Thyroid hormone replacement started within 2
  weeks of age can normalize cognitive development
• Serum T4 and TSH to confirm diagnosis
• Levothyroxine 10-15 mcg/kg
• Goal normalize TSH, keep T4 in upper end of age
  appropriate range
• Thyroid scan/ultrasound to identify functional
  tissue
• Referral to pediatric endocrinologist
• Parent education (med administration, compliance)

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Management of the Neonate

• Monitor T4 TSH
• At 2 and 4 weeks after starting therapy
• Every 1-2 months in 1st 6 months of life
• Every 3-4 months between 6 months 3 years
• Every 6-12 months until growth is completed
• More frequently with dosage changes, abnormal
  labs, compliance concerns
• (Palla Srinivasan, 2013)

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Implications for Family

• Economic

• Social

• Follow up care/appointments conflict with
  parents work
• Financial cost of healthcare
• May need public assistance

• Increased time demands on parents
• Difficult to find childcare for disabled/sick
  child
• Decreased participation in social events
• (Reichman, Corman, Noonan, 2008)

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Implications for FamilyEmotional

• Caring for sick/disabled child can be stressful
• May feel guilt, blame, reduced self esteem ? poor
  mental health
• Parents may have decreased/altered interaction
  with their other children
• May decide not to have other children
• (Reichman, Corman, Noonan, 2008)

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Summary

• Thyroid hormones are important for the bodys
  metabolic processes.
• Alterations in thyroid function occur during
  pregnancy.
• Hypothyroidism can result in mental retardation
  stunted growth in the fetus.
• Therapy is replacement with Levothyroxine in both
  pregnancy neonatal period.
• Families may experience financial, social,
  emotional hardships if their infant is diagnosed.

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References

• American Academy of Pediatrics, American Thyroid
  Association, Lawson Wilkins Pediatric Endocrine
  Society (2011). Clinical report Update of
  newborn screening and therapy for congenital
  hypothyroidism. Pediatrics, 117(6),2290-2303.
  Retrieved from http//pediatrics.aappublications.o
  rg/content/129/4/e1103.full
• Blackburn, S. T. (Ed.). (2013). Maternal, fetal,
  neonatal physiology A clinical perspectivce
  (4th ed). Maryland Heights, MO Elsevier
  Saunders.
• De Groot, L., M. Abalovich, E. K., Alexander, N.,
  Amino, L., Barbour, R., Cobin, C., Eastman,, J.,
  Lazarus, D., Luton, S., Mandel, J., Mestman, J.,
  Rovert, S., Sullivan, (2012). Management of
  thyroid dysfunction during pregnancy and
  postpartum An Endocrine Society clinical
  practice guideline. The Journal of Clinical
  Endocrinology Metabolism, 97, 2543-2565.
  Retrieved from https//www.endocrine.org/search?q
  hypothyroidism20pregnancy20guidelines
• National Library of Medicine. (2014). Neonatal
  hypothyroidism. Retrieved from http//www.nlm.nih.
  gov/medlineplus/ency/article/001193.htm
• Palla, M.M. Srinivasan, G. (2013). Thyroid
  disorders. In T.L. Gomella, M. D. Cunningham,
  F. G. Eyal (Eds.), Neonatology Management,
  procedures, on-call problems, diseases, and drugs
  (7th ed., 908-913). New York, NY McGraw Hill.
• Reichman, N. E., Corman, H., Noonan, K. (2008).
  Impact of child disability on the family.
  Maternal and Child Health Journal, 12(6),
  679-683. doi10.1007/s10995-007-0307-z
• Rose, S. R. (2011). Thyroid disorders. In R.J.
  Martin, A. A. Fanaroff, M. C. Walsh (Eds.),
  Neonatal-perinatal medicine Diseases of the
  fetus and infant (9th ed., 84483-85930). Saint
  Louis, MO Elseviere.