Transcript Hypothyroidism During Pregnancy Rosa Carranza University

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
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
Pathophysiology:
Review 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)
Pathophysiology:
pregnancy 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)
Impact on the fetus
 Fetus dependent on maternal T4 in 1st 10-12 weeks
 Thyroid hormones
for brain development
 Contribute to maturation of retina, cochlea, lung, bones,
& thermogenesis
 Hypothyroidism can lead to cretinism - mental
retardation & stunted physical growth
Clinical
Manifestations
Widely separated sutures
Large fontanelles
Short arms/legs
Umbilical hernia
Macroglossia
Mental retardation
Hypotonia
Jaundice
Poor feeding
(National Library of Medicine, 2014)
Diagnostic Evaluation of Newborn
Maternal/Family
History
Physical Exam
Serum T4/TSH
if NBS abnormal
Newborn
Screening
(NBS) Program
Thyroid Uptake
Scan or
Ultrasound
Treatment Options:
Maternal Hypothyroidism Diagnosed Before Pregnancy
 Levothyroxine adjustment for TSH < 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).
Treatment Options:
Maternal Hypothyroidism Diagnosed During
Pregnancy
 Identify high risk women by medical history & exam
 Goal: Normalize thyroid function ASAP
 Start Levothyroxine & titrate dose for TSH < 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).
Management of the Neonate
 Thyroid hormone replacement started
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)
of
Management of the Neonate
Monitor T4 & TSH:
 At 2 and 4 weeks after starting
therapy
Normalize
TSH
 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)
T4 in upper
end age
appropriate
range
Implications for Family
Economic
Social
Follow up care/appointments
conflict with parent’s work
Increased time demands on
parents
Financial cost of healthcare
Difficult to find childcare for
disabled/sick child
May need public assistance
Decreased participation in social
events
(Reichman, Corman, & Noonan, 2008)
Implications for Family
Emotional
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)
Summary
 Thyroid hormones are important for the body’s 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.
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.org/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=hypothyroidism%20pregnancy%20guidelines
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. doi:10.1007/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.