ESPE Abstracts

Background: GnRH analogs (GnRHa) have been used in the management of central precocious puberty (CPP). The response to GnRHa treatment are evaluated by clinical, hormonal, and ultrasonographic criteria. However, a single parameter to define the adequacy of therapy is not defined. The uterine artery pulsatility index (PI), defined as systolic peak – diastolic peak/average speed of maximum flow, is an expression of vascular compliance in the uterine artery. Circulating estrogen reduce vascular resistance and, consequently, the PI values.

Objective and hypotheses: We aimed to evaluate the PI accuracy in the monitoring of GnRHa treatment in patients with CPP.

Methods: 56 girls referring to our hospital from September 2005 to March 2013 for CPP were enrolled. Tanner stage, LH peak measurement after GnRH stimulation, uterine and ovarian diameters and volumes, and PI values were compared at baseline and 6 months after treatment beginning. Paired t-test analysis was performed.

Results: Before and after 6 months of treatment PI values were 3.9±1.19 and 5.6±1.44 (P<0.0001), longitudinal uterine diameter (mm) were 41.3±6.57 and 36.7±5.4 (P<0.0001), LH peak values (mU/ml) were 19.4±12.8 and 0.8±0.82 (P<0.0001), and breast development were 2.75±0.97 and 2.0±1.17. After 6 months of treatment PI increased in 48 patients (86%), longitudinal uterine diameter decreased in 46 patients (82%), LH peak value decreased ≤3 mU/ml in 54 patients (96%), and Tanner stage decreased or was stable in 53 patients (95%).

Conclusion: The PI, together with longitudinal uterine diameter and clinical evaluation, could be an accurate and non-invasive parameter for the evaluation of the GnRH-analog treatment efficacy, avoiding the need for a stimulation test.