Thyroid Disorders

Question 1

Thyroid changes in pregnancy

Answer 1

lower TSH in 1st trimester 2/2 increased beta hcg
higher total TH 2/2 increased SBG
thyroid increases 30% size
Baby needs thyroid hormone

Question 2

T3 or T4 transferred to fetus?

Answer 2

T4

Question 3

Symptoms of Graves?

Answer 3

HYPERTHYROID:
palpitations, tremors, GOITER, nervous, wt loss, sweating, tachycardia, diarrhea, heat intolerance, HTN, insomnia, Lid lag/retraction

Question 4

Risk of uncontrolled thyrotoxicosis

Answer 4

maternal heart failure and preE

Question 5

Graves disease risk to fetus

Answer 5

Hyperthyroidism: 2/2 thyroid stimulating immunoglobulin
Hypothyroidism: 2/2 TSH binding inhibitory Igs
mothers thyroid iodine ablation/thyroidectomy prior to pregnancy who don’t need thiomide, babies are more at risk 2/2 no THIOMIDE for suppression

Question 6

Is fetal thyrotoxicosis still possible even if mother has now only a history of Graves?

Answer 6

YES

Question 7

How would you definitively diagnose fetal thyrotoxicosis?

Answer 7

Fetal umb cord blood sampling (only do if cannot definitively rule out based on sono and clinical data

Question 8

Signs/symptoms in fetal thyrotoxicosis?

Answer 8

Fetal tachy
Goiter
hydrops
IUGR
Stillbirth
PTB

Question 9

Do we treat subclinical hyperthyroid?

Answer 9

NOPE–meds can cross placenta and affect fetus

Question 10

Hashimotos cause?

Answer 10

antithyroid peroxidase Abs, iodine deficiency

Question 11

Daily iodine needed?
Pregnant women?
Lactating?

Answer 11

150 mcg
Pregnant: 220mcg
Lactating: 290mcg

Question 12

Untreated hypothryoid risks in preg?

Answer 12

SAB, preE, PTB, placental abruption, stillbirth, IUGR, impaired neuropsych development…but rare that anti TPO ab cross placenta and cause fetal hypothyroidism

Question 13

If thyroid slightly enlarged in pregnant pt, no other symptoms, do you screen for thyroid disease?

Answer 13

Nope. Thyroid can increase in size by 30%. Only do if significantly enlarged goiter, nodules, symptoms.

Question 14

Maternal complications of hyperthyroid

Answer 14

Cardiomyopathy, heart failure
Pulmonary hypertension
Thyrotoxicosis (rare)

Question 15

How do you confirm thyrotoxicosis? Should you wait for labs to come back to treat?

Answer 15

Get TSH and free T4, but don’t wait for labs to come back

Question 16

Should you deliver emergently in thyroid storm?

Answer 16

No, usually fetus gets better as mother gets better. Avoid delivery if possible.

Question 17

Thyroid sono detects nodules reliably beyond what size?

Answer 17

0.5cm

Question 18

How do you biopsy suspicious thyroid nodule?

Answer 18

FNA

Question 19

When does fetal thyroid become active?

Answer 19

After 12 wks

Question 20

What if mother received thyroid radiation in 1st trimester before 12 wks?

Answer 20

It’s ok. Most fetuses not affected.

Question 21

When can you remove maternal thyroid if thyroid ca dx?

Answer 21

1st or 2nd trimester…but usually wait until after delivery