The frequency of salivary progesterone sampling and the diagnosis of luteal phase insufficiency

A profile of salivary progesterone concentrations, based on daily samples taken over a full menstrual cycle, provides a detailed picture of changes in luteal function, at the expense of analyzing a large number of samples. Strain can be placed on analytical services by assaying daily samples instead of one or a few serum (or saliva) samples. This study sought to determine the minimum number of salivary progesterone determinations which adequately describe luteal function. Daily salivary progesterone levels from 215 cycles, of which 29 cycles had progesterone profiles indicative of luteal phase insufficiency, were analyzed to ascertain the efficiencies of various sampling patterns of reduced frequency. A single mid-luteal salivary progesterone estimation or the mid-luteal Lenton progesterone index (n = 4) satisfactorily reflected the normal luteal phase, but a frequency of one sample every 3 days over the luteal phase (n = 5-6) was necessary to allow recognition of a short luteal phase or poor progesterone surge.