The current expectation is that every ovulatory menstrual cycle will have a luteal phase (the time from egg released until the next flow) that lasts approximately 14 days. It is simple, ovulation covers half of the expected, classical 28-day menstrual cycle. That fits with another current concept, "All regular month-apart menstrual cycles are ovulatory.
" "We discovered a wide variety of luteal phase lengths, even in healthy premenopausal women who needed two cycles in a row that were both of normal cycle length and ovulatory in order to join the original study," said this study's first author, Sarah Henry, BSc (hons), MD, now in her University of British Columbia family practice residency who did this research as a medical student. "Although the luteal phase was not predictable in length, it was usually less variable than the follicular phase." The findings, just published in Human Reproduction , show that the luteal phase is quite variable.
It was documented using the validated Quantitative Basal Temperature© (QBT©) method. By QBT©, a normal luteal phase length is ≥10 days; short luteal cycles are <10 days. "This year-long study is a rare one examining within-woman follicular phase and luteal length variabilities," said Sonia Shirin MD, MHSc, CeMCOR research associate and co-author who worked with Dr.
Henry on statistical analyses. "We studied 53 healthy women's cycles over about a year; all had at least 8, and an average of 13 menstrual cycles." An amazing thing is tha.