Master the board step 3

Master the Boards: USMLE Step 3
Abnormal Vaginal Bleeding
A 31-year-old woman complains of 6 months of metromenorrhagia. The patient
states that she started menstruating at age 13 and that she has had regular menses
until the past 6 months. The pelvic examination, including a Pap smear, is
normal. She has no other significant personal or family history. What is the next
step in management?
a. Obtain ß-hCG
b. Obtain LH, FSH levels
c. Perform a pelvic ultrasound
d. Recommend oral contraceptive pill
e. Recommend progestin-only pill
Answer: A. Irregular bleeding in reproductive age should always be evaluated first
for pregnancy. If pregnancy is ruled out, workup for anatomical causes of bleeding or
anovulation can be started.
Primary Amenorrhea
Primary amenorrhea is diagnosed with absence of menses at age 14 without secondary
sexual development or at age 16 with secondary sexual development.
Diagnostic Testing
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Physical exam and ultrasound:
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Are breasts present or absent? Breasts indicate adequate estrogen production.
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Is a uterus present or absent on ultrasound?
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Karyotype, testosterone, FSH
Breasts Present
Breasts Absent
Uterus Present
Workup as secondary amenorrhea
• Imperforate hymen
• Vaginal septum
• Anorexia nervosa
• Excessive exercise
• Pregnancy before the first menses
Order FSH level and karyotype
• Gonadal dysgenesis (Turner’s syndrome)
– X0 karyotype, FSH elevated
• Hypothalamic–pituitary failure
– XX karyotype, FSH low
Uterus Absent
Order testosterone levels and karyotype
• Müllerian agenesis
– XX karyotype, normal testosterone for
female
• Complete androgen insensitivity (testicular
feminization)
– XY karyotype, normal testosterone for male
RARE
• Not clinically relevant
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