The Rotterdam criteria (2003) for PCOS require 2 of 3 features. Which of the following correctly describes the ultrasound criterion?
- A Ovarian volume >10 mL on either ovary
- B ≥12 follicles measuring 2–9 mm on either ovary OR ovarian volume >10 mL ✓
- C ≥20 follicles measuring 2–9 mm on either ovary with increased stromal echogenicity
- D Antral follicle count >25 on transvaginal ultrasound
Correct answer: B. ≥12 follicles measuring 2–9 mm on either ovary OR ovarian volume >10 mL
Explanation
The original Rotterdam 2003 ultrasound criterion for PCOS is polycystic ovarian morphology: ≥12 follicles measuring 2–9 mm per ovary AND/OR ovarian volume >10 mL (on either ovary), excluding ovarian cysts or dominant follicles. In 2018, ESHRE updated the threshold to ≥20 follicles per ovary using high-frequency transducers, recognizing improved ultrasound resolution. However, the classic Rotterdam threshold of ≥12 remains widely cited in NEET-PG context. Ovarian volume >10 mL alone (option A) is insufficient — the criterion includes either follicle count OR volume.
Reference: Shaw's Textbook of Gynaecology, 17th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.