This prospective observational study investigates the changes in serum steroid intermediates assessed by liquid chromatography-mass spectrometry (LC-MS/MS) in adolescents and young women with polycystic ovary syndrome (PCOS), before and after oral contraceptive (OCP) treatment.

The study enrolled 56 female patients aged 13-21 years with a diagnosis of PCOS according to Rotterdam criteria. At baseline, all participants underwent LC-MS/MS steroid profiling. A subgroup of 15 patients received oral contraceptive therapy based on clinical indication, independent of the study protocol. A second LC-MS/MS steroid analysis was performed at 6 months in this subgroup. The primary aim was to investigate the effect of OCP on the steroid biosynthesis profile. The study was approved by the Istanbul University Ethics Committee (Approval ID: 2019/822) and conducted between January 2020 and December 2021.

Inclusion Criteria:

• Diagnosis of PCOS based on Rotterdam criteria
• Age between 13 and 21 years
• No hormonal treatment in the 3 months prior to study enrollment
• Consent provided

Exclusion Criteria:

• Congenital adrenal hyperplasia
• Cushing's syndrome
• Pregnancy
• Use of hormonal medications within 1 year prior to baseline

Adolescent females aged 13 to 21 years diagnosed with polycystic ovary syndrome (PCOS) according to the Rotterdam criteria. All participants were evaluated at the Istanbul Faculty of Medicine between 2020 and 2021. Baseline serum steroid profiles were analyzed using LC-MS/MS in all participants. A subset of 15 patients received oral contraceptive treatment for medical indications and had follow-up hormonal evaluations at 6 months.