Billings Ovulation Method


Billings Ovulation Method is a mucus-only method for natural family planning and is one of the oldest and most researched methods in the world. The method uses sensation and mucus observations to open and close the fertile window, which make the method suitable for both normal length menstrual cycles as well as long menstrual cycles, for example during breastfeeding. With only four simple rules, the Billings Ovulation Method is very easy to use.

Several studies have been conducted on the Billings Ovulation Method which show birth control effectiveness of 97.4-100% with perfect use. With typical use the effectiveness has been 77.7-99.5% No population level estimated typical user rates are available. The method has been researched among a population of blind women who were found to be able to use the method successfully.

Billing Ovulation Method was developed by the doctors John and Evelyn Billings in Australia in the 1960s together with emeritus professor James Brown, who did research on female hormones during the menstrual cycle, and emeritus professor Erik Odeblad who did research on cervical crypts and mucus. This research has laid the ground for other modern fertility awareness based methods as well.

Teachers in Billings Ovulation Method are trained according to the manual from WOOMB (World Organisation Ovulation Method of Billings) and are trained to teach the method for both avoiding and achieving pregnancy and refer clients to a medical practitioner in case of concerns over menstrual cycle health.

Although the Billings Ovulation Method is a natural family planning method (NFP) the teaching material and training do not contain religious content. Combining other non-hormonal birth control methods such as condoms with charting is not recommended in the Billings Ovulation Method because use of other methods might affect its observational routine for cervical mucus.


    • Bhargava H, Bhatia JC, Ramachandran L, Rohatgi P, Sinha A (1996). Field trial of billings ovulation method of natural family planning. Contraception 53: 69–74. DOI: 10.1016/0010-7824(95)00269-3. 
    • Brown J (2000). Ovarian Activity and Fertility and the Billings Ovulation Method. Ovulation Method Research and Reference Center of Australia. 
    • Odeblad E (1994). The Discovery of Different Types of Cervical Mucus and the Billings Ovulation Method®. Bulletin of the Ovulation Method Research and Reference Centre of Australia, Volume 21, Number 3, pp. 3-35.
    • Qian S, Zhang D, Zuo H, et al. (1999). Evaluation of the effectiveness of Natural Fertility Regulation Programme in China. Presented at The Woman of Today and Her Identity: Femininity, Fecundity and Procreation, Centre for Study and Research in the Natural Regulation of Fertility, Universita Cattolica del Sacro Cuore, Rome, Italy, on 8 September 2000. 
    • World Health Organization (1981). A prospective multicentre trial of the ovulation method of natural family planning. I. The teaching phase. Fertility and Sterility, 36(2): 152-158. DOI: 10.1016/S0015-0282(16)45671-2. 
    • World Health Organization (1981). A prospective multicentre trial of the ovulation method of natural family planning. II. The effectiveness phase. Fertility and Sterility 36(5):591-8. DOI: 10.1016/s0015-0282(16)45856-5



    English (UK)