The Diagnostic Value of Pelvic Ultrasound in Girls with Central Precocious Puberty

The gonadotropin-releasing hormone (GnRH) stimulation test is the gold standard for differentiating central precocious puberty (CPP) from exaggerated thelarche (ET). Because of this test's limitations, previous studies have clarified the clinical and laboratory factors that predict CPP. The present study investigated the early diagnostic significance of pelvic ultrasound in girls with CPP. The GnRH stimulation test and pelvic ultrasound were performed between March 2007 and February 2015 in 192 girls (aged <8 years) with signs of early puberty and advanced bone age. Ninety-three of 192 patients (48.4%) were diagnosed as having CPP and the others (51.6%) as having ET. The CPP group had higher uterine volumes (4.31±2.79 mL) than did the ET group (3.05±1.97 mL, p=0.03). No significant differences were found in other ultrasonographic parameters. By use of receiver operating characteristic curve analysis, the most predictive parameter for CPP was a uterine volume of least 3.30 mL, with an area under the curve of 0.659 (95% confidence interval: 0.576-0.736). The CPP group had significantly higher uterine volumes than did the ET group, but there were no reliable cutoff values in pelvic ultrasound for differentiating between CPP and ET. Pelvic ultrasound should be combined with clinical and laboratory tests to maximize its diagnostic value for CPP.