Thyroid Disorders Flashcards
Thyroid changes in pregnancy
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
T3 or T4 transferred to fetus?
T4
Symptoms of Graves?
HYPERTHYROID:
palpitations, tremors, GOITER, nervous, wt loss, sweating, tachycardia, diarrhea, heat intolerance, HTN, insomnia, Lid lag/retraction
Risk of uncontrolled thyrotoxicosis
maternal heart failure and preE
Graves disease risk to fetus
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
Is fetal thyrotoxicosis still possible even if mother has now only a history of Graves?
YES
How would you definitively diagnose fetal thyrotoxicosis?
Fetal umb cord blood sampling (only do if cannot definitively rule out based on sono and clinical data
Signs/symptoms in fetal thyrotoxicosis?
Fetal tachy Goiter hydrops IUGR Stillbirth PTB
Do we treat subclinical hyperthyroid?
NOPE–meds can cross placenta and affect fetus
Hashimotos cause?
antithyroid peroxidase Abs, iodine deficiency
Daily iodine needed?
Pregnant women?
Lactating?
150 mcg
Pregnant: 220mcg
Lactating: 290mcg
Untreated hypothryoid risks in preg?
SAB, preE, PTB, placental abruption, stillbirth, IUGR, impaired neuropsych development…but rare that anti TPO ab cross placenta and cause fetal hypothyroidism
If thyroid slightly enlarged in pregnant pt, no other symptoms, do you screen for thyroid disease?
Nope. Thyroid can increase in size by 30%. Only do if significantly enlarged goiter, nodules, symptoms.
Maternal complications of hyperthyroid
Cardiomyopathy, heart failure
Pulmonary hypertension
Thyrotoxicosis (rare)
How do you confirm thyrotoxicosis? Should you wait for labs to come back to treat?
Get TSH and free T4, but don’t wait for labs to come back
Should you deliver emergently in thyroid storm?
No, usually fetus gets better as mother gets better. Avoid delivery if possible.
Thyroid sono detects nodules reliably beyond what size?
0.5cm
How do you biopsy suspicious thyroid nodule?
FNA
When does fetal thyroid become active?
After 12 wks
What if mother received thyroid radiation in 1st trimester before 12 wks?
It’s ok. Most fetuses not affected.
When can you remove maternal thyroid if thyroid ca dx?
1st or 2nd trimester…but usually wait until after delivery
