The solutions are behavioral, not chemical or mechanical. To think otherwise is to imply that men and women are powerless to direct and control their sexual urges. From a public health point of view, there is no cheaper method than natural family planning. Charting of mucus can be done very simply. In poor countries, a simple notebook and pencil marks are used in place of the stamp charts.
Some countries favor the symptothermal method.
In this hemisphere, thermometers are not expensive, while supplies are still problematic in rural Africa and Asia. In many parts of the world the intrauterine device is widely used. If the device is not inserted skillfully, the woman's uterus can be perforated. Even when properly placed, it can be the channel for bacteria or viruses to enter the uterus and cause pelvic infection. Another reason is the fear of infertility caused by pelvic infection.