Induction of the LH Surge in Premenarchal Girls Confirms Early Maturation of the Hypothalamic–Pituitary–Ovarian Axis

Purpose:To determine whether premenarchal girls exhibit positive estradiol feedback similar to regularly cycling adult women when given exogenous estradiol.Methods:This was a prospective clinical cohort study at 2 institutions. Nine girls and 6 women received a 7-day course of transdermal estradiol designed to produce physiologic, mid-cycle circulating estradiol levels. Participants collected daily morning urine for luteinizing hormone (LH), estradiol metabolites (E1c), and progesterone metabolites (Pdg), corrected for creatinine. Main outcomes were percentage increase in LH from nadir to peak and the absolute value of peak LH between the 2 groups, using t testing and linear mixed-effects modeling.Results:All participants exhibited a positive feedback response to estradiol. Adult women had a 532.8% (95% confidence interval [CI]: 253.7-1119) increase in LH after estradiol exposure; premenarchal girls had a 497.9% increase (95% CI: 274.5-903.2; P = .86). The absolute value of the LH surge in women was 9.50 ...