Quantitative viscoelastic and sperm penetration measurements were made on individual human cervial mucus samples collected from several ovulatory menstrual cycles. An inverse relationship was found to exist between these two mucus properties, with peak penetrability seen during the ovulatory phase of the cycle when viscoelasticity was lowest. Limited sperm penetration was also observed with follicular phase mucus. When mucus was collected three times daily, the first sample of the day showed reduced pH values and elevated percentage of nondialyzable solids (NDS) and viscoelastcity. Rates of mucus production were calculated for two cycles; the highest rate was seen during the ovulatory phase, with the follicular and luteal phases showing approximately 50% and 30% of this rate, respectively. Limited disparities were noted between midcycle changes in percentage of mucus NDS and viscoelasticity and in blood levels of total estrogens.
PIP: Characteristics of human cervical mucus were determined at different times of the day during different phases of the menstrual cycle. Mucus and blood were taken 3 times daily from ovulatory donors. Determinations were made as follows: mucus penetrability as measured by the capillary tube penetration test, mucus viscoelasticity (VE) as measured by a microrheometer, wet weights and nondialyzable solids (NDS), mucus pH, cellularity, ferning, and spinnbarkeit. 1st samples of the day collected at 9 a.m. differed markedly from later samples in that pH was lower and %NDS or VE was higher; reproducibility was much improved for the later 2 samples. Rate of mucus production varied as much as 10-fold from luteal to ovulatory phases, the rate being highest near ovulation. Mucus penetrability was inversely related to VE and also peaked in the ovulatory phase. Degree of variation in VE over the course of the menstrual cycle differed greatly from 1 individual to another, a finding that may be important in the prediction of ovulation.