Background: This study aims to explore the diagnostic significance of basal sex hormone levels and pelvic B-mode ultrasound in the context of central precocious puberty (CPP) in female children. Methods: A cohort study was conducted at the 2024. The study enrolled female children exhibiting early breast development before the age of 8 and subjected them to gonadotropin-releasing hormone (GnRH) stimulation tests. Subsequently, the participants were categorized into a CPP cohort and a nonCPP cohort, each comprising 75 individuals. Comparative analysis was performed on the basal luteinizing hormone (LH) levels, uterine length and ovarian volume between the two cohorts. Results: The results show no significant differences were observed in age and body mass index (BMI) between the CPP and non-CPP groups (both p> 0.05). However, basal LH levels, uterine length, and ovarian volume were significantly higher in the CPP group compared to the non-CPP group (all p < 0.05). Binary logistic regression analysis revealed that basal LH levels, uterine length, and ovarian volume were independent risk factors for CPP in female children (all p < 0.05). Receiver Operating Characteristic (ROC) curve analysis showed that the area under the curve (AUC) for basal LH, ovarian volume, and uterine length were 0.823, 0.752 and 0.730, respectively. The combined diagnosis of these three factors significantly improved diagnostic performance, with an AUC of 0.931(95% confidence interval (CI) : 0.891-0.972), a sensitivity of 88.00%, and a specificity of 86.70%. Conclusions: The integration of basal levels of sex hormones and pelvic B-mode ultrasound holds considerable importance in the diagnosis of CPP in young girls, offering a non-invasive, accessible and cost-effective method for clinical assessment. Therefore, its utilization is highly recommended.
