['To assess whether birth weight influences the metabolic and hormonal profile of adolescents with polycystic ovary syndrome (PCOS).', 'Retrospective study.', 'University outpatient clinic.', 'One hundred seventy consecutive adolescents 12 to 19\xa0years of age with PCOS, 15 of whom were small for gestational age (SGA), and 75 healthy female aged-matched adolescents as controls.', 'Physical evaluations, fasting blood samples for measuring endocrine and metabolic parameters, and an oral glucose tolerance test.', 'Physical, endocrine, and metabolic features.', 'The birth weights of adolescents with PCOS as well as those with hyperinsulinemic or insulin resistance were similar to those of the control group. The PCOS SGA adolescents had basal insulin (15.93 ± 7.16 μU/mL vs. 10.97 ± 5.79 μU/mL) and homeostasis model assessment of insulin resistance values (3.2 ± 1.54 vs. 2.19 ± 1.28) that were statistically significantly higher than in the control group. The mean levels of total testosterone in the SGA adolescents with PCOS were above the upper limit of the normal range (0.80\xa0ng/mL).'] Do insulin resistance and hyperandrogenism have no substantive association with birth weight in adolescents with polycystic ovary syndrome?