Prediction of ovulation with basal body temperature.

Basal body temperature (BBT) is used extensively to monitor ovulation in the treatment of infertility. There are well-defined methods of interpreting the BBT graph retrospectively that identify a presumptive day of ovulation. The prediction of ovulation through utilization of the BBT graph (strictly concurrent interpretation) is adversely influenced by temperature fluctuation and cycle length variability. The BBT graph can be very useful when its interpretation is well defined and its limitations understood.