The method that uses the body's natural physiological changes and symptoms to identify the fertile and infertile phases of the menstrual cycle is called Natural Family Planning (NFP) or Fertility Awareness-Based Methods (FABMs). These methods involve tracking several physiological indicators, including changes in cervical mucus, basal body temperature, and other ovulation-related symptoms like breast tenderness and cervical position and texture. Key features of this method:
- Cervical Mucus Method: Observing changes in cervical mucus consistency and texture throughout the cycle. Fertile mucus is clear, stretchy, and slippery, like raw egg whites, signaling ovulation time.
- Basal Body Temperature Method: Tracking body temperature daily to identify the rise in temperature after ovulation indicating the post-ovulatory infertile phase.
- Symptothermal Method: Combining basal body temperature, cervical mucus observations, and other symptoms to identify fertile and infertile phases.
- These methods rely on the awareness of hormonal changes reflected in physical symptoms to determine when a woman is fertile or infertile.
These methods allow couples to plan or avoid pregnancy by recognizing the natural fertile window with high accuracy when applied correctly.