Supplementary Material for: Doppler Assessment of the Uterine Arteries is a Valuable Adjunct Tool for the Evaluation of Efficacy of Gonadotropin-Releasing Hormone Agonist Therapy in Girls with Central Precocious Puberty

Introduction: Pelvic ultrasound has been studied for the follow-up of girls with precocious puberty during gonadotropin-releasing hormone agonists (GnRHa) therapy. The addition of Doppler evaluation of uterine arteries needs to be further investigated. We aimed to evaluate the accuracy of the uterine artery pulsatility index (PI) for monitoring GnRHa therapy in girls with precocious puberty.Methods: This is a retrospective cohort study of girls with central precocious puberty (CPP) and early and fast puberty (EFP) treated with GnRHa. We included girls who underwent pelvic ultrasound and Doppler imaging of the uterine arteries before and during therapy. Analyses included uterine artery PI and uterine, endometrial, and ovarian measurements. Receiver operating characteristic (ROC) curves with cutoffs determined by the Youden index were used for data analysis.Results: In total, 28 pairs of PI measurements (54% of girls with CPP, 46% with EFP) before and during GnRHa therapy were included in the paired-sample analysis. The median duration of treatment at the time of ultrasound was 11.5 (7; 19) months. The mean PI was significantly higher during GnRHa therapy than at baseline (6.5 ± 1.8 vs. 4.0 ± 1.6, respectively, P < 0.001). A total of three girls met clinical and laboratory criteria for treatment failure. ROC curve analysis showed that the PI was able to identify an effective GnRHa therapy with a mean area under the curve (AUC) of 0.967 ± 0.04 (P < 0.001), and the PI cutoff point of 5.4 held a sensitivity of 84%, specificity of 100%, and accuracy of 86%.Conclusion: We found a significant increase in the PI during GnRHa therapy, which reflects higher resistance in the blood flow to the uterus, indicating effective pubertal hormone suppression.