Cervical mucus: the biological marker of fertility and infertility

The ovulation method provides a woman with an awareness of her cervical mucus pattern. This enables her to mark the beginning and end of the fertile phase of the cycle as well as the time of maximum fertility. Not only is the time of ovulation located but also there is recognition of infertility in the absence of ovulation. The key to understanding is the concept of the basic infertile pattern which precedes the commencement of follicular development; the key to successful use is competent teaching. After preliminary considerations on the fertile phase the determination of ovulation and the aspect of periodic abstinence two basic studies comparing clinical and hormonal observations are reviewed showing how accurately the cervical mucus reflects ovarian activity. Understanding the basic infertile pattern and the two sets of rules (the early day rules and peak rule identifying respectively the beginning and end of the fertile period) is basic to the application of the ovulation method. Criteria for the ideal family planning method and the importance of quality teaching are presented. Two problems requiring attention in NFP are restrictive terminology in data collection and a lack of fully developed and positive approach to periodic abstinence.