Font size
WorksheetsThyroid Dz in Pregnancy
Total questions: 15
Worksheet time: 10mins
What changes occur in thyroid hormones 1st trimester?
Decreased TSH
Increased TBG (thyroid binding globulin)
Decreased TRH
Increased T4
Reference range for TSH in first trimester?
Same as non-pregnant patient
Lower range decreased by 0.4 millionunits/L
Upper range reduced by 0.5 millionunits/L
Upper range increased by 0.5 millionunits/L
Referance range for T4 & T3 in pregnancy?
Same as non-pregnant patient
Increased by ~50% compared to non-pregnant
Decreased by ~50% compared to non-pregnant
Increased by ~50% but only after 16 weeks EGA
Who should have thyroid testing in pregnancy?
Personal or family history of thyroid dz
Type I DM
Clinical suspicion of thyroid dz
Mildly enlarged thyroid
Pts with hyperemesis gravidarum
Which of these cross the placenta?
Thyroid inhibitory antibodies (antithyroid peroxidase Ab)
Thyroid stimulating immunoglobulin
TSH binding inhibitory immunoglobulins (aka thyrotropin binding inhibitory immunoglobulins)
Thioamides (PTU & Methimazole)
T4 only in 3rd trimester
Risks of untreated hyperthyroidism
Low birth weight
Miscarriage & stillbirth
Increased risk of pre-eclampsia with severe features if poorly control
Increased risk of maternal heart failure
Preterm delivery
Subclinical hyperthyroidism (low TSH with normal T4) does not need to be treated in pregnancy
True
False
Neonates born to mothers with Graves Dz who were treated with thyroidectomy or radioactive iodine prior to pregnancy are not at risk of neonatal graves disease
True
False
How do you treat hyperthyroidism in pregnancy?
Beta blockers (propranolol 10-40mg TID to QID) in any trimester
PTU 100-600mg daily divided into 3 doses in any trimester
Methimazole 5-30mg daily divided into 2 doses in any trimester
What labs should be monitored in patient with hyperthyroidism on treatment?
CBC every month to screen for agranulocytosis
TSH every month
T4 +/- T3 every month
Treatment of thyroid storm or thyrotoxic heart failure in pregnancy
Emergent delivery
PTU 1000mg PO then 200mg PO q6hrs
Iodine 1-2 hours after PTU
Steroids
Beta blocker
Risks of untreated hypothyroidism include
Spontaneous abortion & Stillbirth
Pre-eclampsia
Preterm birth
Placental abruption
Impaired neuropsych development & low birth weight
Treatment for hypothyrodism in pregnancy
Continue current dose of levothyroxine
Increase current dose by 25% at time of pregnancy confirmation
For new diagnosis start levothyroxine 1-2 mcg/kg daily or approximately 100mcg daily
How to monitor hypothyroidism during pregnancy
Check TSH every trimester
Check T3 & T4 levels every trimester
Check TSH every 4-6 weeks
Check T3 & T4 levels every 4-6 weeks
Goal TSH level for pregnant patients with hypothyroidism
0.5-2.5 milliunits/L
0.5-5 milliunits/L
Number doesn't matter if patient is asymptomatic
>0.5 milliunits/L
