The anterior pituitary response to a gonadotropin-releasing hormone challenge test in normal older reproductive-age women*†*Supported in part by the National Institutes of Health grant R01HD 18967 (M.R.S.), National Institutes of Health P-50 HD 12629 (W.J.B), and M01 RR00037 (Clinical Research Center), Bethesda, Maryland.†Presented in part at Annual Meeting of The American Fertility Society, San Antonio, Texas, November 5 to 10, 1994.