Evaluation of puberty by verifying spontaneous and stimulated gonadotropin values in girls.

Background: Changes in pharmacological agents and advancements in laboratory assays have changed the gonadotropin-releasing hormone analog stimulation test.
Objective: To determine the best predictive model for detecting puberty in girls.
Subjects: Thirty-five girls, aged 2 years 7 months to 9 years 3 months, with central precocious puberty (CPP) (n=20) or premature thelarche/premature adrenarche (n=15).
Methods: Diagnoses were based on clinical information, baseline hormones, bone age, and pelvic sonogram. Gonadotropins and E2 were analyzed using immunochemiluminometric assay. Logistic regression for CPP was performed.
Results: The best predictor of CPP is the E2-change model based on 3- to 24-h values, providing 80% sensitivity and 87% specificity. Three-hour luteinizing hormone (LH) provided 75% sensitivity and 87% specificity. Basal LH lowered sensitivity to 65% and specificity to 53%.
Conclusions: The E2-change model provided the best predictive power; however, 3-h LH was more practical and convenient when evaluating puberty in girls.