Table 1.

Normal menstrual cycle used for the inclusion criteria.

Parameter	Normal	Abnormal
Frequency	Normal ⩾24 days to ⩽38 days	Absent (No periods or bleeding) Amenorrhea Infrequent > 38 days
Duration	Normal ⩽ up to 8 days	Prolonged > 8 days
Regularity	Regular variation (shortest to longest) ⩽7–9 days	Irregular (shortest to longest ⩾10 days)
Volume	Normal	Light Heavy