(101) Pelvic ultrasound in girls with central precocious puberty

Background: Pelvic ultrasound is a simple, non-invasive, available, and low-cost test, with an important role in the assessment of precocious puberty. The objective of the study was to analyze the uterine and ovarian volume of patients with Central Precocious Puberty (CPP).

Methods: A cross-sectional and retrospective study was carried out with patients with CPP treated from November 2021 to October 2022. They were considered to have CPP if baseline LH > 0.3 IU/mL or pubertal test with leuprorelin 3.75 mg (LH after 2 hours of intramuscular injection > 8 mIU/mL), advancement >= 12 months or 2 standard deviations on bone age, thelarche before 8 years of age and progression of secondary sexual characteristics. Uterine volume >= 3.5 ml and ovary volume >= 2 ml were considered suggestive of pubertal stimulation. To check the existence of correlation between the tested variables, we used the Spearman correlation coefficient as they are variables without normal distribution. The significance level was α=0.05. The study was approved by the Research Ethics Committee (CAAE 39249220.5.000.5345).

Results: The mean age was 7.39 years, the mean height was 132 cm and the mean BMI was 17.34 kg/m². The mean age of the thelarche and pubarche was 7 years and 11.62 years for the mothers' menarche. The average measures were respectively: uterine volume was 7.59 ml; volume of the largest ovary was 3.55 ml and the pulsatility index of the uterine arteries was 4.06. The average difference between chronological age and bone age was 18.75 months. The mean values of hormonal basal status were SDHEA 74.94 mcg/dL, LH 3.13 mIU/mL and estradiol 31.86 pg/mL. Tanner's median was M3P2.
Analyzing uterine volume, a positive and statistically significant correlation was observed between it and baseline estradiol (r=0.501; p=0.007), basal LH (r=0.715; P< 0.0001) and with the volume of the largest ovary (r=516; p=0.006). We found no correlation between uterine volume and SDHEA (r=0.228; p=0.349). Furthermore, uterine volume >= 3.5ml was found in 75% of our patients (21/28).
Analyzing the volume of the largest ovary, there was no correlation between it and SDHEA (r=0.354; p=0.137), basal LH (r=0.350; p=0.073) or basal Estradiol (r=0.127; p=0.526) but was positive between it and the uterine volume (r=516; p=0.006). Besides this, the volume of the largest ovary >= 2 ml was found in 81% of our patients (22/27).

Conclusions: Uterine volume seems to be a good parameter for expressing estrogenic stimulus and ovarian volume was a good parameter for expressing gonadotrophic stimulus. Both, the uterine volume and the ovary volume can help in the diagnosis of CPP and also in the follow up to show progression or stabilization of puberty.