Timing of onset of menses after GnRH agonist treatment for central precocious puberty

Objectives To understand possible predictors of the onset of menses after gonadotropin-releasing hormone agonist treatment cessation in girls with central precocious puberty (CPP). Methods This exploratory post hoc analysis of a phase 3 and 4 trial of girls with CPP treated with once-monthly intramuscular leuprolide acetate examined onset of menses after treatment completion using a time-to-event analysis. Pretreatment and end-of-treatment chronologic age (CA), bone age (BA)/CA ratio, and Tanner breast stage; pretreatment menses status; and end-of-treatment BA and body mass index (BMI) were studied as potential factors influencing the onset of menses. Results Median time to first menses after stopping treatment was 18.3 months among 35 girls (mean age at onset of treatment, 6.8 years) examined. Of 26 girls experiencing menses, 11 (42 %) menstruated at 16–21 months after stopping treatment. Most girls with pretreatment BA/CA≥1.4 started menstruating very close to 18 months after stopping treatment; those with less advanced BA/CA experienced menses at 9–18 months. End-of-treatment BA/CA≥1.2 was associated with a quicker onset of menses (14.5 vs. 18.5 months for BA/CA<1.2, p=0.006). End-of-treatment BA≥12 years predicted longer time to menses. No relationship with time to menses was observed for pretreatment menarche status, pretreatment or end-of-treatment Tanner breast stage (<3/≥3) or CA (<6/≥6 or ≤11/>11), or end-of-treatment BMI percentiles (<85.6/≥85.6 and <92.6/≥92.6). Conclusions Pretreatment menarche status or CA do not appear to predict onset of menses, but pre- and end-of-treatment BA/CA may be helpful in anticipating time to first menses after stopping treatment.