Hypothyroidism

Question 1

Who do you screen for hypothyroidism?

Answer 1

• Type 1 DM
• History of fetal growth restriction
• History of stillbirth
• Infertility
• Symptoms of thyroid
• Family history of thyroid disease
• Living in an area of deficiency

Question 2

How do you screen for hypothyroidism?

Answer 2

TSH reflex to free T4

Question 3

How do you follow a patient with a diagnosis of hypothyroidism and not on medications?

Answer 3

• Evaluate baseline TSH
• Evaluate every trimester if stable

-If TSH and FT4 levels becomes abnormal, initiate treatment as recommended as follows:
1-2 micrograms/kg daily or approximately 100 micrograms daily of Levothyroxine

• Make medication adjustments by 25-microgram to 50-microgram increments until TSH values normalize or reaches goal
• Repeat TSH every 4 weeks until goal is reached

Question 4

How do you follow a patient with a diagnosis of hypothyroidism and on medications?

Answer 4

-Once the TSH level reaches goal, it should be evaluated every trimester as medication adjustment mays be necessary

Question 5

What laboratory testing do you order on a patient with hypothyroidism?

Answer 5

TSH, free T4

Question 6

What are your target function tests for hypothyroidism management in pregnancy?

Answer 6

Based on data from the American Thyroid Association, current trimester specific ranges for the TSH are:

first trimester 0.1 to 2.5 milli-international units per liter

second trimester 0.2 to 3 milli-international units per liter

third trimester 0.3 to 3.0 milli-international units per liter.

Question 7

How are thyroid function tests altered by pregnancy?

Answer 7

hCG human chorionic gonadotropinn is closely related to thyroid stimulating hormone (TSH).

hCG can bind to the TSH receptors present in thyroid tissue and act like a weak form of TSH to cause the thyroid to produce and release more thyroxine and triiodothyronine

Question 8

How do you manage levothyroxine in pregnancy?

Answer 8

-If TSH and FT4 levels becomes abnormal, initiate treatment as recommended as follows:

1-2 micrograms/kg daily or approximately 100 micrograms daily of Levothyroxine

-Make medication adjustments by 25-microgram to 50-microgram increments until TSH values normalize or reaches goal

Question 9

What are the obstetric/fetal risks with poorly controlled hypothyroidism?

Answer 9

spontaneous abortion
preeclampsia
preterm birth
abruptio placentae
fetal death
low birth weight
impaired neuropsychologic development of the infants. antithyroid antibodies can cause fetal hypothyroidism.