Observational study pelvic ultrasound a useful tool in the diagnosis and differentiation of precocious puberty in Chinese girls

Rapid and noninvasive diagnosis on and differentiation between normal, central precocious puberty (CPP), and isolated precocious puberty (IPP) is imperative before a decision can be made with gonadotropin-releasing hormone (GnRH) agonist treatment. Our study aims to evaluate such a role by pelvic ultrasound. We consecutively enrolled 84 cases of IPP (59 with premature thelarche/ pubarche and 25 with premature menarche), 47 CPP, and 177 age-matched normal controls. The IPP and CPP were diagnosed by clinical examination and GnRH-stimulation test and confirmed by over 2 years’ follow-up. All subjects underwent pelvic ultrasound examination for length, width, thickness, volume of uterine/cervix/ovaries, fundal/cervical thickness ratio, endometrial thickness, and averaged maximal diameter of largest follicles. Statistical comparisons of these sonographic parameters between disease groups were made according to age intervals. It was found that between CPP and normal girls, 10 and 12 ultrasound parameters differed significantly in the >6 to 8 and >8 to 10 years age interval, respectively. Cervical thickness and endometrial thickness was the best discriminating parameter in the 2 intervals by receiver operating characteristic (ROC) curve analysis, and the cutoff, sensitivity and specificity associated with was 0.73 cm, 93.30%, 85.70%, and 0.26 cm, 76.92%, 100%, respectively. Between CPP and IPP, 2 and 5 parameters differed significantly in the >6 to 8 and >8 to 10 years age interval. Cervical length was the best discriminating parameter in both age intervals. The cutoff, sensitivity, and specificity associated were 1.49 cm, 93.33%, 55.17%, and 1.88 cm, 100%, 71.43%, respectively; Finally between normal and IPP girls, 4, 7, and 5 parameters differed significantly in the 0 to 6, >6 to 8, and >8 to 10 years intervals, respectively. Ovarian thickness, ovarian width, and cervix thickness was the best parameter for the 3 age interval respectively, and the cutoff, sensitivity and specificity associated were 0.98 cm, 76.46%, 84.85%, 1.39 cm, 85.71%,73.81%, and 0.75 cm, 90.48%, 64.21%, respectively. Our results indicate that pelvic ultrasonography could serve as a complementary tool for differentiation between normal girls and girls with different forms of sexual precocity in China. The best discriminating parameter changes according to precocity forms and age intervals.