The value of simple tests in the detection of human ovulation.

Cervical mucus viscosity (CMV) and fern test (FT), leukocyte alkaline phosphatase (LAP) activity, basal body temperature (BBT) and serum luteinizing hormone (LH) levels were determined during 31 normal menstrual cycles of 29 volunteers. The day of the serum LH surge was taken as a reference point in evaluating the reliability and sensitivity in predicting ovulation of the other tests studied. Serum LH surge was accompanied by a sudden decrease in CMV, an increase in LAP activity, a gradual increase in FT and biphasic changes of BBT. In about 95% of cycles studied, the lowest values of CMV and peak values of LAP activity appeared on the day of the serum LH surge or one day before or one day after. The lowest point of the BBT coincided with the LH surge in only 26% of cycles. In 53% of cycles, the span was greater than one day before or after the LH peak. The FT corresponded to the LH surge in only 33% of the cycles, while in an additional 33% the preovulatory FT response occurred more than one day before or after the LH surge. The results indicate that CMV and LAP tests are rapid, simple and reliable for monitoring follicular maturation and the timing of ovulation when carried out daily, and may be of value in monitoring treatment during the induction of ovulation.