USMLE Step 2 CK Lecture Notes 2019: Obstetrics/Gynecology (Kaplan Test Prep)

OB TRIAD

Hypothyroidism

Diagnosis. Diagnosis is confirmed with an elevated TSH.

Management. Increase supplemental thyroid hormone by 30% in pregnancy.

Table I-10-2. Thyroid   Disorders   in  Pregnancy

Hyperthyroid Hypothyroid

Most    common  cause Graves    disease Hashimoto’s thyroiditis

Diagnostic  criteria ↓  TSH,    ↑   free    T4  TSHR-

antibody

↑   TSH,    ↓   free    T4

Complication    if

untreated

Thyroid storm,  IUGR Anovulation,   spontaneous abortion

Outcome if  properly

treated

Normal  pregnancy Normal    pregnancy

Treatment   medications 1st trimester:  PTU

2nd+3rd trimester:

methimazole

Synthroid   (↑  dose    30% above

prepregnancy)

↑   TSH level

↓   free    T 4     level

Anovulation

If  uncontrolled,   it  is  associated  with    spontaneous abortion;   however,    if

pregnancy   continues,  the infant  is  healthy.    

If  controlled  with    appropriate thyroid replacement,    normal  fertility   and

pregnancy   outcomes    are noted.