Breast skin temperature rhythms in relation to ovulation.

Breast skin temperatures have been monitored at 30-min intervals throughout wake-span for the whole or part of the menstrual cycle of women aged 20-37 years using both manual and automatic (chronobra) methods of measurement. Circadian breast skin temperature rhythms have been mathematically characterized and rhythm parameters assessed in relation to the estimated time of ovulation. Data generally indicate that there is a peri-ovulatory rise in breast temperature. Computer simulation and practical experiments, based on changes in the residual sums of squares from target values obtained for days in the cycle prior to ovulation, have indicated that this peri-ovulatory increase in temperature is possibly detectable within 24 h. The use of the chronobra and associated statistics may be of value in signalling the onset of the infertile phase of the menstrual cycle.