Time relationships between basal body temperature and ovulation or plasma progestins

Area of Science:

• Reproductive Endocrinology
• Gynecology
• Chronobiology

Background:

• Basal body temperature (BBT) is a commonly used method for ovulation tracking.
• Accurate ovulation timing is crucial for conception and fertility awareness.

Purpose of the Study:

• To evaluate the reliability of Basal Body Temperature (BBT) charting for precise ovulation timing.
• To correlate BBT changes with hormonal shifts during the ovulatory period.

Main Methods:

• Analysis of BBT curves in 38 spontaneous menstrual cycles.
• Correlation of BBT nadir and rise with luteinizing hormone (LH) surge and progesterone levels.

Main Results:

• The BBT nadir typically coincided with the onset of the LH surge.
• The first significant BBT increase occurred approximately 8 hours post-ovulation.
• Temperature rise correlated with progesterone and 17-hydroxyprogesterone increases, with a 24–36 hour delay.

Conclusions:

• Basal body temperature charting is an unreliable method for precise ovulation timing.
• BBT may offer general insights into ovulation but lacks clinical precision for exact diagnosis.