(47) Establishing Normative Findings of Ovarian Anatomy and Sex Hormones through Puberty

Background: There are limited data on normal pelvic anatomy in pre-, peri-, and post-pubertal biological females, and current literature lacks correlative data on ovarian volume and sex hormones throughout puberty. Prior studies suggest complex models for increases in ovarian volume, as well as in most sex hormones, across puberty. A more thorough understanding of normal anatomical development and the correlation of hormonal changes is needed to better understand pathology that disproportionately affects adolescents with ovaries, such as torsion and polycystic ovarian syndrome.

Methods: Serial pelvic MRI studies, as well as hormone panels, were obtained every 8-10 months in typically-developing adolescent girls ages 8-17y during the follicular phase of their menstrual cycles. Two cohorts were included, one enrolling at 8y and the other 12-14y. Ovarian volumetry was performed by segmentation using Vitrea Software (Minnetonka, MN, USA), and the values for the two ovaries were averaged. Volumes were excluded if they were not able to be adequately calculated bilaterally or if the calculated value included an apparent cyst. Estradiol concentration was measured by chemiluminescence immunoassay and testosterone by liquid chromatography-tandem mass spectrometry, with lower limits of detectability of 5pg/mL and 8ng/dL, respectively. Ovarian volume was plotted against age, estradiol, and testosterone.

Results: The cohort included data from 31 individuals with a total of 99 visits during which MRIs were performed and hormone panels were collected; 17 subjects were enrolled at age 8-9y and 14 subjects at age 12-14y. Ovarian volume averages were included for 68 visits in 28 individuals. The mean number of visits for this cohort was 3.2 (SD 1.6, range 1-6); mean years older at final visit was 1.7y (SD 1.4y, range 0-4y). The cohort identified as 48.4% white, 25.8% Black/African American, 16.1% Asian, 6.5% multiple races, and 3.2% Native American. Additionally, 12.9% identified as Latino or Hispanic. Ovarian volumes generally increased with age and sex hormone concentrations, but showed complex individual trajectories.

Conclusions: These data represent an early exploration of the correlations between ovarian volume and sex hormone concentrations in puberty in healthy adolescent girls. Strengths of the data include its racial and ethnic makeup, which is representative of the United States’ population, as well as its longitudinal nature, with serial studies for most participants. Further analyses with this cohort can be performed to elucidate best-fit models for these relationships, as well as to characterize more detailed anatomical findings on MRI in pubertal girls.