Data for postmenarchal girls under the age of 18 and premenopausal women over the age of 45 are difficult to discern as ovulatory disorders have a relatively high prevalence. It is suggested that the ≤9 day threshold for normal be used for this population.
Data from:
- Harlow SD, Lin X, Ho MJ. Analysis of menstrual diary data across the reproductive life span applicability of the bipartite model approach and the importance of within-woman variance. J Clin Epidemiol 2000; 53:722.
Reproduced with permission from Malcolm G Munro, MD, FRCSC, FACOG.
