In evaluating secondary amenorrhea, which test helps assess ovarian reserve?

• A. hCG
• B. TSH
• C. FSH with estradiol
• D. Prolactin

Answer: (C)

Assessing ovarian reserve is about estimating how many viable eggs remain in the ovaries, which helps predict fertility potential in secondary amenorrhea. The pituitary increases FSH when the ovarian response to stimulation is weak, so higher FSH levels (measured on day 3 of the cycle) point to diminished ovarian reserve. Measuring FSH together with estradiol on the same day refines this assessment because estradiol provides context for FSH levels—the combination helps distinguish true ovarian aging from other factors that can alter FSH. In general, a pattern of rising FSH with a corresponding estradiol level supports reduced ovarian reserve and has implications for prognosis and management of fertility.

The other tests target distinct causes of amenorrhea rather than ovarian reserve. hCG is used to detect or trigger pregnancy, not to gauge ovarian follicle pool. TSH assesses thyroid function, which can influence menstrual cycles but doesn’t directly measure how many eggs remain. Prolactin evaluates lactotroph function; elevated prolactin can suppress GnRH and cause amenorrhea, but it does not reflect ovarian reserve. Modern practice also uses anti-Müllerian hormone and antral follicle count as additional reserve measures, but the classic test pair for this purpose is the FSH with estradiol on day 3.