Diagnosing PMOS in adolescents: Criteria, ultrasound limits, and red flags

Cree opens by clarifying that the PMOS name change did not alter diagnostic criteria. Three criteria define the syndrome: irregular menses, clinical or biochemical signs of elevated androgens, and — in adults only — ovarian findings by ultrasound or, when imaging isn't available, anti-Müllerian hormone. For adolescents less than two years post-menarche, irregular cycles mean fewer than 21 or more than 45 days between periods, or any single gap beyond 90 days; adults use a tighter 21-to-35-day window. Because ovarian criteria don't apply until eight years post-menarche, Cree explains, adolescents must show both irregular menses and hyperandrogenism — a single criterion places a teen only in an "at risk" category. Appelbaum adds that transvaginal ultrasound often isn't feasible in adolescents who aren't sexually active, transabdominal imaging can't reliably measure ovarian volume or antral follicle count, and normal values for adolescent ovaries remain poorly defined — reasons the field leans on clinical judgment rather than imaging at this age.

She also flags acne as a diagnostic gray area, since it's common in adolescence independent of PMOS, and stresses ruling out mimics like hyperthyroidism and congenital adrenal hyperplasia before finalizing a diagnosis. Maresca notes that the "at risk" category exists precisely so clinicians don't have to wait years to start treatment in a teen who already shows irregular periods, insulin resistance, and hirsutism. Appelbaum reframes irregular menses itself as a vital sign rather than a problem to fix directly — a signal that should prompt metabolic evaluation. Cree closes with a sobering data point: two of her patients were diagnosed with endometrial cancer at age 22, reinforcing that unopposed estrogen from chronic anovulation, not the ovary itself, drives the reproductive risk in PMOS, and that regular withdrawal bleeding matters well before adulthood.

In the next episode, "From Primary Care to Specialist: Managing PMOS and Insulin Resistance," Maresca and Cree map out when primary care should manage PMOS versus refer, and Cree argues insulin resistance deserves just as much attention as androgens.