[Natural family planning (symptothermal method) and objective ovulation parameters--a pilot study]

Area of Science:

• Reproductive Endocrinology
• Gynecology

Background:

• The symptothermal method of Natural Family Planning (NFP) relies on various physiological indicators to determine fertility.
• Accurate identification of the fertile window is crucial for effective family planning and conception timing.

Purpose of the Study:

• To evaluate the accuracy of NFP parameters in relation to ovulation detection.
• To determine the reliability of NFP indicators for identifying the beginning and end of the fertile phase.

Main Methods:

• A double-blind pilot study involving 20 cycles from six experienced female NFP users and teachers.
• NFP parameters (mucus characteristics, basal body temperature) were correlated with ovulation confirmed by ultrasound and hormonal analysis (LH, oestrogen).
• Focus on calculating the first and last day of the fertile phase relative to maximal follicular diameter (day 0).

Main Results:

• LH peak occurred at -0.7 days, and peak mucus at -0.58 days relative to maximal follicular diameter.
• Fertile phase indicators (F1, F2, F3) appeared significantly before ovulation (day 0).
• Post-ovulation indicators (L1, L2) appeared days after ovulation; 95% of cycles correctly identified the fertile phase start, but only 85% identified the end.

Conclusions:

• The symptothermal method, using at least two indicators, is effective in identifying the start of the fertile phase.
• Further refinement is needed to improve the accuracy of detecting the end of the fertile phase using NFP methods.
• Natural fertility signals observed by users accurately indicated ovulation in most cycles studied.