Impact of the newly recommended antral follicle count cutoff for polycystic ovary in adult women with polycystic ovary syndrome

Abstract STUDY QUESTION What is the impact of the newly recommended antral follicle count (AFC) cutoff for polycystic ovary (PCO) on the diagnostic status of polycystic ovary syndrome (PCOS)? SUMMARY ANSWER Among patients with phenotypes requiring the presence of PCO for diagnosis, approximately half (48.2%) were excluded from having PCOS based on the new AFC cutoff, although these excluded women had worse metabolic and hormonal profiles than the controls and were indistinguishable from the remaining patients with regard to major hormonal and metabolic parameters. WHAT IS KNOWN ALREADY In the Rotterdam criteria, PCO is defined as either 12 or more follicles measuring 2–9 mm in diameter or an increased ovarian volume >10 cm3. Recently, an international PCOS guideline development group recommended an AFC threshold for PCO of ≥20 in adult women when using transducers with a high-resolution frequency, including 8 MHz. STUDY DESIGN, SIZE, DURATION The current study used a case control design. PARTICIPANTS/MATERIALS, SETTING, METHODS PCOS was diagnosed according to the Rotterdam criteria. Ultrasonography examinations were conducted with wide band frequency (5–9 MHz) transvaginal transducers and the centre frequency was 8 MHz. In patients who show both irregular menstruation and hyperandrogenism (HA), a diagnosis of PCOS can be made irrespective of the ovarian criteria change. Patients who were diagnosed according to HA and PCO (n = 86) or irregular menstruation and PCO (n = 443) were initially included among a total of 1390 adult women with PCOS (aged 20–40 years). Regardless of the AFC, if the ovarian volume is ≥10 cm3, a diagnosis of PCO can still be made. Thus, only patients who had an ovarian volume of