Methods
Five methods, clearly explained.
Each modern method reads a different combination of biological signals. Here's how they compare.
Marquette
9 MIN READ
The Marquette Method
Developed at Marquette University in the 1990s, the Marquette Method combines an at-home hormone monitor with optional cervical mucus and temperature observations.
- Perfect use
- 98–99%
- Typical use
- 92–98%
- Biomarkers
- Urinary hormone monitor · Optional cervical mucus · Optional BBT
Billings
6 MIN READ
The Billings Ovulation Method
Developed by Drs. John and Evelyn Billings beginning in the 1950s, the Billings Method relies entirely on observation and interpretation of cervical mucus patterns.
- Perfect use
- 98%+
- Typical use
- 78–95%
- Biomarkers
- Cervical mucus observation
Creighton
6 MIN READ
The Creighton Model FertilityCare System
A standardized refinement of the Billings approach used widely in NaProTechnology medical practice for both family planning and diagnosis of underlying reproductive health conditions.
- Perfect use
- 99%
- Typical use
- 85–95%
- Biomarkers
- Standardized cervical mucus observation
Sympto-Thermal
7 MIN READ
Sympto-Thermal Method
Combines temperature, mucus, and other biomarkers to cross-confirm the beginning and end of the fertile window. The German Sensiplan variant is one of the most rigorously studied methods.
- Perfect use
- 99.6%
- Typical use
- 98% (Sensiplan study)
- Biomarkers
- Basal body temperature · Cervical mucus · Optional cervical position
Standard Days
4 MIN READ
Standard Days Method
A calendar-based method appropriate only for users with consistently regular cycles between 26 and 32 days. Often visualized with the CycleBeads tool.
- Perfect use
- 95%
- Typical use
- 88%
- Biomarkers
- Cycle length
FEMM
4 MIN READ
FEMM (Fertility Education & Medical Management)
FEMM combines fertility education with app-based charting and a medical management pathway. It's designed to help women identify hormonal patterns and connect those patterns to clinical care.
- Perfect use
- Evidence still emerging
- Typical use
- Evidence still emerging
- Biomarkers
- Cervical fluid observation · Optional LH testing · Bleeding & symptom tracking