The Billings ovulation method

What are the benefits?

Mary Walsh, MBBS, FRACGP, is in general medical practice in Melbourne. She has been in medical practice for 22 years. In 1997 she was elected President of the Ovulation Method Research and Reference Centre of Australia where she is engaged in general practice evaluation research. Dr Walsh is an accredited Billings ovulation method teacher.
Nicholas Tonti-Filippini, BA, MA, is a consultant ethicist and an occasional feature writer on medical issues. At St Vincent's Hospital, Melbourne from 1982-1989 he was Australia's first hospital ethicist and held the position of Director of Bioethics. He is currently a consultant ethicist in private practice and a doctoral candidate in the Department of Philosophy at the University of Melbourne. Mr Tonti-Filippini is conducting some general practice evaluation research with OMR&RCA.

In 1995 the Commonwealth Department of Human Services and Health (DHS&H) commissioned a survey to determine the use of contraceptive methods in Australia by women and men between the ages of 15 and 54 years. Asked which methods they had ever used, 25% said that they had used periods of abstinence/celibacy, 10% the rhythm method, and 7% the Billings ovulation method (BOM). Asked which methods they had used during the past 12 months, 10% of respondents reported using periods of abstinence/celibacy, 3% the rhythm method and 1% the Billings method. The Billings method was the preferred method of 2%, while 2% preferred the rhythm method and 3% preferred periods of abstinence/celibacy.1

It would appear from this that a significant proportion of people surveyed had opted for a natural method of contraception at some point in their life, making knowledge of the infertile period during the cycle important for avoiding pregnancy. As the rhythm method is demonstrably unreliable,2 the ability to observe the mucus symptom which is a reliable indicator for periods of both infertility and fertility in a woman's cycle, becomes very important.3-5 All women in their reproductive years should at least have the option of learning to recognise and interpret their mucus symptom and have access to the self-understanding of their reproductive health and the predictability of their cycle.

Another particular group who would benefit from knowledge of the BOM are those who are sub-fertile and are seeking help to achieve pregnancy. One study has found that the majority of women (74%) seeking help for infertility lack adequate fertility awareness.6 This led the director of the NSW Family Planning Association, Dr Edith Weisberg, to remark that women seeking help for infertility should be referred to natural family planning clinics to learn fertility awareness.7

Monitoring ovulation

The majority of women (97%) are easily taught the BOM.8 In a multi-centre international trial by the World Health Organisation, 93% of women were able to chart an interpretable ovulatory mucus pattern in the first cycle.9 The short time of potential fertility around ovulation is a readily detectable phase, marked by secretion of mucus from the cervix of the uterus which produces a sensation of wetness and slipperiness at the vulva and usually visible mucus.10,11 The likely day of ovulation is identifiable as the last day of such a sensation or mucus. The studies of the ovulation hormones correlate with the women's own observations of these symptomatic changes. Menstruation predictably occurs within 11-16 days of ovulation but the length of the preovulatory phase is much more variable and the onset of the potentially fertile ovulatory phase is symptomatically predictable only by the mucus symptom. It is also predictable by daily monitoring of the ovarian hormones for which there is now a home monitor available devised by Emeritus Professor James Brown.3, 12

The use of the Brown meter is taught by BOM teachers for those women who may at times lack confidence in their mucus symptoms. The meter can be purchased by women for self testing or they can bring or send urine samples to NFP centres. Confidence in the mucus observations is usually rapidly restored when women see that the meter results correlate with their own mucus symptom charting. Although temperature taking is explained, it has no value as an indicator for the start of the potentially fertile ovulatory phase and at best is only a secondary indicator of ovulation.2 There are numerous factors affecting temperature that make it a less reliable indicator of ovulation.

Empowering women

The information about mucus observation assists women seeking help for infertility or seeking to avoid pregnancy. Women are able to predict the onset of menstruation, and to monitor their fertility and infertility during: irregular cycles; while breast feeding; after oral contraceptive use; and approaching menopause.4 Importantly, self observation of the cycle can help earlier detection of reproductive tract pathology by recognising disturbance of the normal pattern.5 Understanding how to interpret the mucus symptom thus empowers women in the self management of their reproductive health.

Is BOM successful for avoiding pregnancy?

The teaching of the BOM has become simpler and more accessible. Simplified recording techniques, developed largely through experience in developing countries and teaching across language and cultural differences, (greatly expanded in recent years in China), has been very successful and made the method more user friendly. In the WHO multi-centre study of 1976-1981, method effectiveness of the BOM was shown to be three pregnancies per 100 women years (averaged across the participating centres) in those avoiding pregnancy.13 When the learning phase was taken into account this reduced to two pregnancies per 100 women years or a success rate of 98%. However, a recent field trial conducted in China involving 1235 women using the BOM to avoid pregnancy over 12 months (a total of 14 820 women months of use), resulted in just five pregnancies and no method related pregnancies.14 This compared to 21 pregnancies in 673 women in the same study using an IUD over the same 12 month period (7 580 women months of use). A recent very large trial conducted in India (32 957 woman months and 2059 women over 21 months) had a method pregnancy rate of 0.86 phwy (+/-0.3) a 99.14% method effectiveness.15

Successful outcomes in teaching fertility and infertility awareness have resulted from the collaboration between medical scientists and women in the community trained as BOM teachers, and their clients.5

Patient information sources

There are some 200 BOM teachers working around Australia, and the Commonwealth Department of Health and Family Services provides funding for training and accreditation of BOM teachers by the Ovulation Method Research and Reference Centre of Australia and of symptothermal teachers by the Australian Council of Natural Family Planning. However, most men and women seek information about contraception from their local doctor or their chemist. In the DHS&H survey, 67% of respondents said that their local doctor was the service that they would most likely use to arrange contraception, and 28% nominated their chemist.1

Evidently, whether or not women obtain information about the BOM and learn to identify their periods of fertility and infertility will depend largely on the attitude of their local doctor or their chemist to the BOM and his or her knowledge and willingness to refer for instruction.

References

  1. Reark Research P/L. A survey about usage of contraception methods and linked protection against sexually transmitted diseases and access to information about sexual health and family planning by Australian females and males 15-54. Prepared for the Department of Human Services and Health, Commonwealth of Australia February, 1995.
  2. Gross B A. Natural family planning indicators of ovulation. Clin Reprod Fertil 1987; 5:91-117.
  3. Brown J B, Harrisson P, Smith M A, Burger H G. A study of returning fertility after childbirth and during lactation by measurement of urinary oestrogen and pregnanediol excretion and cervical mucus production. J Bioscience 1985; (suppl 9)5.
  4. Billings E L. The simplicity of the ovulation method and its application in various circumstances. Acta Eur Fertil 1991; 22(1):33-36. 2. Blake D, Smith D, Bargiacchi M, Gudex G. Fertility awareness in women attending a fertility clinic. Aust NZ J Obstet Gynaecol 1997; 37(3):350.
  5. Hilgers T W. The medical applications of natural family planning. Omaha: Pope Paul VI Institute Press, 1991.
  6. Blake d, Smith D, Bargiacchi, M, Gudex G. Fertility awareness in women attending fertility clinic. Aust NZ J Obstet Gynaecol 1997; 37(3):350
  7. Bonfiglioli C. Knowledge the key to improved fertility. Aust Doctor Weekly Oct 1997.
  8. World Health Organisation. A prospective multicenter trial of the ovulation method of natural family planning, V. Psychosexual aspects. Fertil Steril 1987; 47(5):765-772.
  9. World Health Organisation. A prospective multicentre trial of the ovulation method of natural family planning, I. The teaching phase. Fertil Steril 1981; 36(2):152-158.
  10. World Health Organisation. A prospective multicentre trial of the ovulation method of natural family planning, III. Characteristics of the menstrual cycle and of the fertile phase. Fertil Steril 1983; 40(6):773-778.
  11. Billings J J. The validation of the Billings ovulation method by laboratory research and field trials. Acta Eur Fertil 1991; 22(1):9-15.
  12. Brown J B, Harrisson P, Smith M A, Burger H G. Correlations between the mucus symptoms and the hormonal markers of fertility throughout reproductive life. Ovulation Method Research and Reference Centre of Australia, Melbourne, 1981.
  13. World Health Organisation. A prospective multicentre trial of the ovulation method of natural family planning, II. The effectiveness phase. Fertil-Steril 1981; 36(5):591-598.
  14. Qian S Z, the Jiangsu Family Health Institute. Letter to Dr J J Billings 28 July 1997, reporting the results of a just completed field trial involving more than 1600 cases over twelve months. A report of the results of the field trial has been accepted for publication in the Chin Med J and has been accepted for publication in the J Fert Steril.
  15. Bhargava H, Bhatia J C, Ramachandran L, Rohatgi P, Sinha A. Indian Medical Council "Field trial of Billings Ovulation Method of Natural Family Planning". Contraception 1996; 53:69-74

© Copyright The Royal Australian College of General Practitioners 1998.