Ovarian and Uterine Findings in Pelvic Sonography Comparison Between Prepubertal Girls, Girls With Isolated Thelarche, and Girls With Central Precocious Puberty

Objective. To describe pelvic sonographic findings in girls as old as 7 years, to compare prepubertal girls with girls who had isolated thelarche or central precocious puberty, and to verify the accuracy of sonographic variables for distinguishing prepubertal girls from girls with central precocious puberty. Methods. Ninety-six prepubertal girls and 2 reference groups (8 girls with isolated thelarche and 8 with idiopathic central precocious puberty) were included. Ovaries were classified morphologically as homogeneous, paucicystic, macrocystic, multicystic, and having isolated cysts. Receiver operating characteristic curves were used to choose the best cutoff points. Results. Chronologic and bone age were correlated with uterine length, area, and volume and ovarian volume in prepubertal girls (P <.0001). Ovarian morphologic characteristics in prepubertal girls differed significantly from those of the reference groups (P <.0001). The best cutoff points were uterine length of 4.0 cm, uterine area of 4.5 cm 2 , uterine volume of 3.0 cm 3 , and ovarian volume of 1.0 cm 3 . Conclusions. Uterine and ovarian growth are proportional to age in prepubertal girls. Mean ovarian volume greater than 1 cm 3 showed 100% sensitivity and specificity for discriminating between prepubertal girls and girls with central precocious puberty. Microcysts are common in prepubertal girls, but the presence of 6 or more follicles up to 10 mm in diameter may suggest central precocious puberty in girls younger than 8 years.