Changes in enzyme levels in human cervical mucus during the menstrual cycle.

Cervical mucus is a complex secretion produced by the endocervical epithelium. A comparative analysis of 30 enzymes was carried out on 15 women during their periovulatory period (days 10 to 16 of the menstrual cycle). Nine different enzymes were always found to be present in the cervical mucus. Changes in enzymatic activity were further studied in two of the women, one with a normal (27-day) and the other with a short (20-day) menstrual cycle. The data were compared with those for the same enzymes in the saliva of these two women. Each woman's ovulation time was determined through hormone measurements in urine and blood, as well as by recording basal body temperature and by Billing's method. Our results indicate that a maximum peak occurs for several enzymes during the periovulatory period.