Billings natural FP method: correlation of subjective signs with cervical mucus quality and ovulation

Daily self-appraisal of the degree of vulvar humidity sensation by highly motivated and trained volunteers was correlated to actual cervical mucus quality patterns and time of ovulation. Sixty-two ovulatory cycles were studied. Humidity degrees reported by the women showed a highly significant correlation with simultaneous values of cervical mucus spinnbarkeit and crystallization. On the other hand, ovulatory days were also closely related to the days reported with maximal (+++) humidity degree. In summary, the correct appraisal of vulvar humidity may provide consistent information on both cervical sperm penetrability and ovulation predictions; these in turn could complement each other in ascertaining the potentially fertile period of the cycle.