Normal variation in the length of the luteal phase of the menstrual cycle: identification of the short luteal phase

TLDR

Normal probability plots were used to assess the homogeneity of 327 luteal phases, defined as the interval from the luteinizing hormone peak to the day before menstruation. The data followed a normal distribution with a mean luteal phase of 14.13 ± 1.41 days, while cycles of 9 days and a minority of 10–12 day cycles were abnormal, yielding a 5.2 % incidence of short luteal phases. Summary.

Abstract

Summary. Normal probability plots were used to assess the homogeneity of a population of 327 luteal phases from apparently ovulatory menstrual cycles. The length of the luteal phase was defined as the interval (in days) following but not including, the luteinizing hormone peak, up to and including the day before onset of menstruation. A small sub‐set of the population consisted of cycles with abnormally short luteal phases but the majority of the data followed a normal frequency distribution which gave a mean (± SD) for normal luteal phase length of 14.13 (± 1.41) days. It was estimated that all cycles with a luteal phase 9 days were abnormal, and that 74%, 22% and 2% respectively of cycles with luteal phases of 10, 11 and 12 days were also abnormal. The total incidence of short luteal phases defined as above was 5.2%.