Single luteal phase serum progesterone assay as an indicator of ovulation

Abstract

The availability of a rapid, accurate serum progesterone assay would alleviate many of the problems of patient inconvenience and discomfort encountered with the classical methods of ovulation detection. With the use of a competitive protein binding technique, by which a single technician can assay 30 or more samples for serum progesterone in one day, a range of daily follicular and luteal phase values was ascertained in a group of normally menstruating women. After a normal luteal phase range was established, single luteal phase serum progesterone sampling was performed in 51 infertile women with regular menses and 35 oligomenorrheic women undergoing clomiphene therapy. In the follicular phase of the cycle, progesterone levels were consistently less than 2 ng. per milliliter. Between 11 and 4 days prior to the onset of menses, in presumptively ovulatory cycles, serum progesterone levels were always 3 ng. per milliliter or greater. Progesterone values in this range were always accompanied by a secretory endometrium and, thus, can be considered presumptive evidence of ovulation.