Daily measurements of salivary progesterone reveal a high rate of anovulation in healthy students

Abstract

Daily concentrations of salivary progesterone (P) were measured from 32 women during a complete menstrual cycle. Seventeen of the subjects were university students and 15 were patients of an infertility clinic (a severe malefactor was verified as the cause of infertility in all of them). Commercially available reagents for radio-immunoassay of serum P were modified for salivary measurements, to yield acceptable precision and sensitivity (40 pmol/1). Good correlation (r=0.93) was found between salivary and serum P concentrations in samples collected simultaneously. The follicular phase levels of salivary P were below 100 pmol/1, and those at the luteal peak were 390±45 pmol/1 (mean±SEM, n=24). From the menstrual salivary P concentration curves we identified the first day of significant elevation above mean follicular levels (T2) and thereafter calculated the cumulative sum of daily P concentrations until 95% of the luteal phase secretion had accumulated (C95). The time needed to reach C95 (designated T95) and logC95 were plotted in coordinates and used as the basis of evaluation of normal menstrual P secretion. The observations were distributed in two groups, one with clearly identifiable T2 and a distinct luteal-phase P (ovulation had occurred) and one with no identifiable T2 and absent luteal-phase P peak (indicative of anovulation). Interestingly, 47% of the student population had an abnormally low menstrual P profile while all the other subjects displayed a clear luteal-phase peak of salivary P. These data provide more evidence for applicability of salivary P measurements for diagnosis of corpus luteam function and highlight the difficulty of selecting representative reference populations in studies on female reproductive endocrinology.

Key Words:

• corpus luteum
• luteal function
• menstrual cycle
• radio-immunoassay