If serum levels of estradiol do not increase after injection of hCG, the patient has

• A. Primary ovarian failure
• B. Pituitary failure
• C. Tertiary ovarian failure
• D. Secondary ovarian failure

Answer: (A)

When you give an LH-like stimulus with hCG, the ovaries should respond by producing estradiol if they are functional. hCG binds to LH receptors on the theca cells to support steroid production, and with the follicular ovarian reserve still intact, granulosa cells can convert androgens to estradiol, raising serum estradiol levels. If there is no rise in estradiol after hCG, that signals the ovarian tissue itself isn’t responding, which points to primary ovarian failure. In contrast, issues upstream in the pituitary or hypothalamus (secondary or tertiary ovarian failure) would not prevent an exogenous LH signal from triggering ovarian estrogen production if the ovaries are still capable, so estradiol would rise in those cases if the ovaries are functional.