Final answer:
The fertility awareness method involves avoiding unprotected vaginal intercourse during the most fertile days of a woman's menstrual cycle, identified through monitoring basal body temperature and changes in cervical mucus. It has a typical-use failure rate of 20 to 25 percent, potentially up to 85 percent.
Step-by-step explanation:
The method which involves calculating the period of ovulation and avoiding sexual intercourse around this time is known as the fertility awareness method. This method of contraception requires a woman to monitor signs of ovulation, such as basal body temperature (BBT) and cervical mucus characteristics, to identify her most fertile days. To prevent pregnancy, a couple would avoid unprotected vaginal intercourse during this fertile period. It's important to note that although BBT can give an indication of when ovulation has occurred, monitoring cervical mucus may be more effective as it can predict ovulation ahead of time, allowing for better planning.
It is crucial to remember that the fertility awareness method is not as effective as other contraceptive methods. Typical-use failure rates can be quite high, ranging from 20 to 25 percent, and sometimes as high as 85 percent for some individuals. The effectiveness of this method is heavily dependent on the consistency and accuracy with which it is practiced.