Standardize the timing of the scan

Few studies that describe the morphology and endocrinology of polycystic ovary syndrome (PCOS) make reference to timing of the menstrual cycle. The baseline ultrasound scan of the pelvis is best performed in the early follicular phase (days 1-3), when the ovaries are relatively quiescent:

• Days 1-3 or 1-5? Days 1-3 most likely to be quiescent. • If oligo-/amenorrheic: random or days 1-3/5 after progestogen-induced bleed? The latter is ideal but for

practical use random scans are performed combined with endocrinology (follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2)) and be prepared to repeat for ovarian volume, etc. if evidence of a dominant follicle (>10 mm).