Researchers have found that a method of natural family planning that uses two indicators to identify the fertile phase in a womans menstrual cycle is as effective as the contraceptive pill for avoiding unplanned pregnancies if used correctly, according to a report published online in Europes leading reproductive medicine journal Human Reproduction today (21 February). 
The symptothermal method (STM) is a form of natural family planning (NFP) that enables couples to identify accurately the time of the womans fertile phase by measuring her temperature and observing cervical secretions. In the largest, prospective study of STM, the researchers found that if the couples then either abstained from sex or used a barrier method during the fertile period, the rate of unplanned pregnancies per year was 0.4% and 0.6% respectively. Out of all the 900 women who took part in the study, including those who had unprotected sex during their fertile period, 1.8 per 100 became unintentionally pregnant.
The lead author of the report, Petra Frank-Herrmann, assistant professor and managing director of the natural fertility section in the Department of Gynaecological Endocrinology at the University of Heidelberg, Germany, said: For a contraceptive method to be rated as highly efficient as the hormonal pill, there should be less than one pregnancy per 100 women per year when the method is used correctly. The pregnancy rate for women who used the STM method correctly in our study was 0.4%, which can be interpreted as one pregnancy occurring per 250 women per year. Therefore, we maintain that the effectiveness of STM is comparable to the effectiveness of modern contraceptive methods such as oral contraceptives, and is an effective and acceptable method of family planning.
A number of fertility awareness based (FAB) methods of family planning have been advocated over the years, but comparisons between different methods and studies of their effectiveness ha
Contact: Emma Mason
European Society for Human Reproduction and Embryology