The Billings Ovulation Method® has been subjected to more scientific research than any other method of regulating fertility. It has been independently trialled by the World Health Organisation and other reputable bodies and found to be as successful for avoiding pregnancy as any method of family planning available today.
In one of the largest trials of the Billings Ovulation Method®, a 12-month multi-centre study in China, the method-related pregnancy rate was zero. The method-related rate is when couples correctly follow all the instructions for the method of birth control. The use-related pregnancy rate was 0.5%. The use-related rate includes couples who misunderstood or did not comply with all the instructions. These results make the Billings Ovulation Method™ as effective as the Pill, and more effective than IUDs, condoms and diaphragms.
Pregnancy rates with perfect use of the Billings Ovulation Method® have fallen close to zero as teaching methods have been refined and updated. Continuation rates are consistently high.
Have a look at this table1 comparing the effectiveness of the Billings Ovulation Method® with different types of birth control:
|Method-related %||Use-related %|
|Billings Ovulation Method®|
|- China trial2
- earlier trials
|Hormone shot (Depo-Provera)||0.3||3 (eg injection overdue)|
|The Pill||0.3||8 (eg missed Pill)|
|Vaginal ring (NuvaRing)||0.3||9 (eg delayed insertion of a new ring)|
|IUD - copper||0.8||2|
|Condoms||2||15 (eg incorrectly applied)|
|Diaphragm||6||16 (eg removed too soon)|
1Figures for the Pill and contraceptive devices taken from Family Planning: A Global Handbook for Providers. Because after insertion no further user action is required for Implanon and the IUD, the figures shown in the use-related column are the pregnancy rates over each device's labelled years of effective use: 3 years for Implanon and 10 years for the copper IUD.
2The China trial involved 992 couples, while the earlier trial with the higher pregnancy rates only involved 122 couples. A larger sample size means a smaller margin of error and more precise estimates. The China trial was conducted in 1996-1997, 20 years later than the trial with the higher pregnancy rates, and so used teaching methods that had been refined and updated. The Chinese government's strict policy in relation to population control was also likely to motivate couples to follow the instructions of the method carefully, giving accurate method-related pregnancy rates. It was also likely to eliminate the effect on the results of couples who don't mind if they get pregnant, and so tend to bend the rules. Thus the China trial gives us an excellent indication of the effectiveness of the Billings Ovulation Method®.