Objective: To evaluate the development of polycystic ovary syndrome (PCOS) during adolescence in girls with a history of premature adrenarche (PA) and to identify clinical, biochemical, and familial factors associated with subsequent PCOS.
Materials and
Methods: This retrospective longitudinal cohort study included 88 girls diagnosed with PA in childhood who were followed until adolescence. PCOS was evaluated during adolescence in clinically indicated participants according to contemporary guideline-based diagnostic criteria.

Results: During follow-up, 15 of 88 girls developed PCOS (cumulative incidence, 17.0%). At PA diagnosis, age, birth weight SDS, and body mass index (BMI)-SDS were similar between the PCOS and non-PCOS groups, and baseline androgen measures did not differ (dehydroepiandrosterone sulfate [DHEA-S], p=0.35; DHEA-S SDS, p=0.80; total testosterone, p=0.87; Δ4-androstenedione, p=0.69). At adolescent/final evaluation, BMI-SDS and ΔBMI-SDS were comparable between the groups (p=0.84 and p=0.58, respectively). Girls who developed PCOS also had menstrual irregularity and clinical hyperandrogenism, with a median modified Ferriman-Gallwey score of 15 (IQR, 11–21). Maternal history of PCOS was more frequent among girls who developed PCOS than among those who did not (7/15 [46.7%] vs. 13/65 [20.0%], p=0.047; OR, 3.50). Total testosterone levels were significantly higher in the PCOS group (p=0.005), whereas DHEA-S and Δ4-androstenedione levels did not differ significantly between the groups.

Conclusion: In girls with PA, adrenal androgen levels at diagnosis did not predict subsequent PCOS. Familial susceptibility was associated with later PCOS development. At adolescent evaluation, total testosterone distinguished girls with PCOS from those without PCOS better than DHEA-S or Δ4-androstenedione. These findings support the continued follow-up of girls with PA through adolescence, with particular attention to familial predisposition, menstrual regularity, and clinical or biochemical hyperandrogenism.