Uterine artery pulsatility index as a functional biomarker of central precocious puberty: a scoping review

Central precocious puberty (CPP) results from the premature activation of the hypothalamic-pituitary gonadal (HPG) axis. Although the GnRH stimulation test remains the gold standard for diagnosis, the uterine artery pulsatility index (PI) has been proposed as a functional indicator of pubertal activation. The aim of this review, which included 11 studies and 1,151 patients, was to summarize the current evidence regarding the diagnostic role of uterine artery PI in CPP evaluation. A consistent inverse relationship was observed between the PI and pubertal progression. The reported PI sensitivity for detecting pubertal onset ranges from 77% to 100%, while the specificity varies between 48% and 100%, depending on the cutoff values and study populations. Diagnostic accuracy improved when the PI was combined with uterine morphometric parameters. In girls with CPP undergoing GnRH agonist therapy, the PI increased significantly during treatment, suggesting its potential role as a marker of therapeutic response. Thus, uterine artery PI represents a physiologically plausible and clinically informative adjunctive tool that suggests HPG axis activation. Although not suitable as a stand-alone diagnostic test, its integration into a multimodal diagnostic framework may enhance the non invasive evaluation and monitoring of CPP.