Which statement regarding amenorrhea is accurate?

• A. Primary amenorrhea is defined as absence of menses for >3 months in a previously menstruating person.
• B. Secondary amenorrhea defined as absence of menses for >2 months.
• C. Primary amenorrhea is defined as failure of menarche by age 15 with secondary sex characteristics or by age 13 without.
• D. Secondary amenorrhea never occurs in adolescence.

Answer: (C)

Understanding how primary amenorrhea is defined is being tested here. Primary amenorrhea means the girl has not begun menstruating by the time puberty would normally have started, with the thresholds depending on pubertal development: if secondary sexual characteristics are present, menarche is expected by age 15; if they are absent, menarche is expected by age 13. Therefore, failure to have menses by age 15 with puberty signs, or by age 13 without signs, fits the definition of primary amenorrhea.

This aligns with the statement that primary amenorrhea is defined as failure of menarche by age 15 with secondary sex characteristics or by age 13 without. The other options misstate the definitions or timing: one describes secondary amenorrhea using an incorrect time frame and misattributes it to primary amenorrhea; another sets an inappropriate duration for secondary amenorrhea; and the last incorrectly asserts that secondary amenorrhea cannot occur in adolescence.