A method of natural family planning that closely monitors two indicators of fertility is just as effective as oral contraception in preventing unwanted pregnancies if used correctly, European researchers report.

Known as the symptothermal method, the technique helps identify the woman’s fertile phase by measuring her temperature and observing cervical secretions. During the identified phases, sexual intercourse is avoided all together or performed using a barrier method, such as condoms.

In the present study, reported in the journal Human Reproduction, the symptothermal method led to an overall annual unplanned pregnancy rate of approximately 0.6 percent per 100 women, which is on par with the rates typically seen with contraceptive pills.

“For a contraceptive method to be rated as highly (effective) as the hormonal pill, there should be less than 1 pregnancy per 100 women per year,” lead author Dr. Petra Frank-Herrmann, from the University of Heidelberg in German, said in a statement.

Among women who always used the symptothermal method correctly, the unplanned pregnancy rate was 0.4 percent. “Therefore, we maintain that the effectiveness of the symptothermal method is comparable to the effectiveness of modern contraceptive methods,” she added.

In the study, the largest to evaluate the effectiveness of the symptothermal method, 900 women were asked to record daily temperature measurements, cervical secretion observations, and sexual behavior. The women included 322 who refrained from intercourse during an identified fertile phase, 509 who used a barrier device during the phase, and 69 who did not document their sexual behavior.

The annual unplanned pregnancy rate among women who abstained from intercourse during fertile phases was 0.4 percent, and the rate among women who used barrier devices during this phase was 0.6 percent.

Roughly 9 percent of women stopped using the symptothermal method due to dissatisfaction or difficulties, which is much lower than the 30 percent drop-out rates reported with some other family planning methods.

According to Frank-Herrmann, books and courses are available that provide instruction in the symptothermal method. “Learning the symptothermal method is usually no problem,” she said, but it does require more time and effort than using a pill

SOURCE: Human Reproduction, February 21, 2007.