Cervical mucus and prediction of the time of ovulation

12 normal ovulatory women were studied during 17 menstrual cycles. The first day on which the women had increasing quantities of 0.1 ml or more clear cervical mucus (IQCCM) was closely related to the time of ovulation as monitored by basal body temperature and radioimmunoassay of serum-luteinizing hormone, follicle-stimulating hormone, estradiol, and progesterone. The results show that the time of ovulation can be predicted clinically without specialized tests by observing the day of onset of IQCCM. The question of whether increased quantities of cervical mucus designate approach of ovulation was studied in 12 normal ovulatory women during 17 menstrual cycles. The quantitative parameter established was called increasing quantities of .1 ml or more of clear cervical mucus (IQCCM) and it was compared with such other generally established ovulation-detecting parameters as basal body temperature and levels of serum luteinizing hormone, follicle stimulating hormone, estradiol, and progesterone, assayed by radiological means. In terms of the relationship between the onset of IQCCM and estradiol or luteinizing hormone peaks, the mean interval from onset of IQCCM to estradiol peak was 1.4+ or -.2 days, range 1-2 days. The luteinizing hormone peak occurred 1.8+ or -.2 days after onset of IQCCM, range 1-3 days. In 8 of 12 women, IQCCM occurred 2 days before luteinizing hormone peak; in 4 reexamined women, the same results were observed about the intervals from IQCCM onset and luteinizing hormone peak. Hence, the results show that the time of ovulation can be predicted clinically without specialized tests by observing the day of onset of IQCCM.