In postmenopausal women, which estrogen predominates?

• A. Estradiol
• B. Estrone
• C. Estriol
• D. Estrone sulfate

Answer: (B)

After menopause, ovarian production of estrogens drops dramatically, so circulating estrogens come mainly from peripheral conversion of adrenal and ovarian androgens in adipose tissue. This aromatization predominantly yields estrone, making it the main circulating estrogen in postmenopausal women. Estradiol levels fall to very low levels, estriol remains generally low in nonpregnant women, and estrone sulfate serves as a reservoir that can be converted back to estrone, but the active predominant estrogen is estrone.