In the last article, we said that the Ovulation Method provided women with a more complete understanding of the phases of fertility and infertility in their cycles. In other words, women need to know not only when ovulation occurs and when infertility begins after ovulation. They also need to recognize the onset of fertility. This is particularly true of nursing mothers, anovular and pre-menopausal women and those with long irregular cycles. Women who are infertile, either occasionally or for prolonged periods of time, need positive evidence of their infertility.

The Ovulation Method provides direct evidence, on a daily basis, of what the body is doing. This is possible because the hormone estrogen, one of the three main hormones, which lead to ovulation, betrays its activity. It stimulates the cervix to produce a certain type of mucus essential to preserving sperm cell life. Thus, when there is no hormonal activity in the early part of the cycle, there is no fertile type mucus. A woman can then conclude that the process, which will lead to ovulation, has not yet begun, and that her system has not yet the capacity to preserve sperm cell life. The number of days during which this situation may persist is variable. Hormonal activity may begin during the time of bleeding in very short cycles, may hold off for quite a few days in longer cycles, or for months in the case of the nursing mother or the anovular woman. In any case, a user of the O.M is instructed in exactly what to look for and how NOT to miss the first evidence of the onset of fertility.

Once a woman detects the onset of fertility, she is able to follow the increasing levels of estrogen in her bloodstream through the increasingly fertile characteristics of the cervical mucus. No internal examination is needed. The mucus falls by gravity to the outside of the body. She can identify the day that the hormones peak in her system because this is the last day of any symptom of fertile-type mucus. She knows that within 24 hours she will ovulate. Fertility persists for a further 48 hours because of the possibility of multiple ovulation and the life span of the ova. This third day past the peak, then, is the concluding day of fertility. The balance of the cycle is infertile. Cases where the body tries to ovulate, fails, and succeeds later in the cycle are no problem because delayed ovulation always will be accompanied by fertile symptoms and users of the O.M. are instructed in how to handle this.

The correlation between the activity of the hormones leading to ovulation and the cervical mucus symptom, the correlation between the peaking of the hormones and the cessation of the symptoms have been tested extensively by endocrinologists and duplicated many times. The Billings have also confirmed the rules of the method using ultrasound techniques, which allow ovulation to be observed directly.

A bibliography of the studies conducted on the hormonal basis of the method is available in  ‘The Billings Method. Controlling Fertility without Drugs or Devices’ by Dr. Evelyn Billings and Ann Westmore.