How does measuring BBT help detect ovulation?
A woman’s normal non-ovulating temperature is between 96 and 99 degrees Fahrenheit, depending on the individual. Following the release of the egg, BBT increases by about half a degree in almost all women. The hormone progesterone, secreted by the ovary after ovulation, heats things up; it also prepares the uterine lining for a possible pregnancy. Body temperature will remain roughly half a degree higher until right before menstruation, when it will return to normal. (If you get pregnant, your temperature will stay higher through the first trimester). If your temperature doesn’t follow this pattern, it might indicate an ovulation problem. Detecting the change Because the spike in body temperature at ovulation is so small, you need a special basal thermometer (available in drugstores) to measure it. A basal thermometer records temperatures in one-tenth of a degree increments instead of the two-tenth increments on fever thermometers. Basal thermometers come in mercury and digital versions
