What are the four major natural family planning methods and how does each determine the time of fertility?
- 1930s Rhythm/Calendar (based on past cycle lengths)
- 1940s Temperature (based on a rise of basal body temperature after ovulation)
- 1950s Sympto-Thermal (based on 3 signs of fertility: mucus, temperature, and cervical changes)
- 1960s Mucus Method (based on presence of fertile mucus before ovulation)
- 1990s Sympto-Hormonal Method (based on the detection of reproductive hormones using a fertility monitor either alone or in conjunction with another sign of fertility such as mucus or temperature)