Thyroid

Question 1

Fetal and neonatal effects of hypothyroidism

Answer 1

If an adequately treated, hypothyroidism can cause low birth weight, miscarriage, stillbirth.
Maternal antibodies can cause fetal thyrotoxicosis (tachycardia and poor growth)

Incidence of neonatal Graves’ disease is unrelated to Maternal thyroid function

Question 2

Antibodies associated with Graves’ disease

Answer 2

TSH receptor stimulating aby

Thyrotropin receptor aby

Question 3

Most common cause of hypothyroidism and the associated antibody

Answer 3

Hashimoto thyroiditis

Anti-thyroid peroxidase antibodies

Question 4

Perinatal risks

Answer 4

SAB, preeclampsia, preterm birth, stillbirth, placental abruption, low birth weight, impaired neuropsychologic development.

Of note, it is rare for thyroid inhibitory antibodies to cross the placenta and cause fetal hypothyroidism

Question 5

Drugs used to treat hyper thyroidism

Associated risks

Answer 5

Thioamides

ProPylthiouracil- rarely causes hepatotoxicity

Methimazole- Avoid in forestry master. Rarely causes embryopathy characterized by esophageal and choanal atresia; aplasia cutis

Both can cause transient leukopenia and agranulocytosis

Question 6

Treatment for hypothyroidism

Goal TSH level

Answer 6

Levothyroxine 1 to 2 µg per kilogram daily

T3 Should not be used in pregnancy as it can cause low T4

Up to 2.5 miU/L

Question 7

Change in thyroid function tests during pregnancy

Answer 7

TSH decreased dt stimulation by HCG, T4 and T3 increase but increasing estrogen increases binding proteins so not net increase

Question 8

Management of thyroid storm

Answer 8

1g PTU then 200 mg q6h

Sodium Iodine 1g IV w8h or potassium iodine 5 drops q8h

Dexamethasone 2mg IV q6

Rehydrate with D5NS

Diazepam

Question 9

What are the preconception risk factors for thyroid disease?

These women should be screened

Answer 9

Age >30
Morbid obesity
Hx of pregnancy loss or preterm delivery
Infertility