For most of her reproductive life, a woman will experience fertile ovulatory cycles. However, all women will experience infertile variants of the ovulatory cycle, particularly during breastfeeding, approach of menarche and menopause, periods of stress, andduring and after hormonal contraception. The hormone patterns and therefore the symptoms in these infertile cycles differ from the fertile ovulatory cycle. Recognizing these variants is particularly important for pregnancy achievement.
Ovulation -the release of an ovum by the ovary and therefore the only timeduring the cycle when the ovum is exposed for fertilization--is the central event ofthe fertile ovarian cycle. It determines the time when pregnancy can occur from an actof intercourse which is the period of 3-4 days (rarely 5-6 days depending on thecervical mucus) before ovulation determined by the fertilizing life span of the spermand up to 24 hours after ovulation determined by the fertilizable life span of the ovum.Outside this time period a woman cannot conceive from an act of intercourse nomatter how hard she tries. Even within this time period, pregnancy from an act ofintercourse is not a certainty, the chances vary depending on the couple and the timingof intercourse in relation to ovulation. Maximum fertility is reached during the periodof 24 hours before ovulation and several hours afterwards. If the chances of pregnancy at this time are 70% per cycle, it takes two cycles for 90% of couples havingintercourse on the most fertile day to achieve pregnancy. If the chances at the beginning of the fertile period are 10% per cycle, it takes 24 cycles for 90% of coupleshaving intercourse at this time to achieve pregnancy
A recent document prepared by the NFP Secretariat of the Australian CatholicSocial Welfare Commission (ACSWC) contains several recommendations relatedto the service and delivery of service of natural family planning methods. A teamof coordinators has been elected who will work closely with both hoand Sympto-Thermal Method groups of NFP teachers. These co-ordinatorsare mostly teachers of one or other method, and therefore it is desirable that as faras possible, they all should understand the methods of natural family planning otherthan their own. One of the suggestions made by the Secretariat of the ACSWC wasthat all teachersshould teach all methods and then invite the couples to choose theone they wish to use. This point needs analysis in the light of the history of themethodologies and in the development of the Ovulation Method™ (Billings). TheWorld Health Organization (WHO) attached the name of Billings to the Ovulation Method™ so that its authenticity could be preserved.
Natural fertility regulation (NFR) methods could provide family planning (avoiding or achieving pregnancy) naturally through conforming to the women's reproductive cycle without the use of drugs or devices. NFR originated about 60 years ago from the rhythmic method, but this method was not scientifically based. Its deadly shortcoming is the prediction of the coming events on the basis of the past rhythm is therefore destined to be inaccurate with a failure rate of more than 20%. A milestone in the NFR study is the discovery of the intrinsic relationship between the cervical mucus, the hormonal balance and the fertility status of women by the Billings group. It was shown that the changes in the cervical mucus correlated with the sex hormone levels in the women, thus the fertile status could be determined by observing the characteristics of the cervical mucus at the vulva. In this way the Billings Ovulation Method (BOM) overcomes the fatal weakness of early natural family planning methods in predicting the current events on the basis of past happening, and lays the foundation of scientific NFR research.