The basal body temperature (BBT) is the temperature of your body before getting out of the bed in the morning. If you keep track of this temperature during a menstrual cycle then it can be a simple way of determining if you are ovulating or not.
Most of the time ovulation related disorders are the main reason behind infertility in women. Therefore, many ob-gyns ask the patient to prepare a BBT chart when they begin the process of conceiving. If any abnormality is detected during the process, it can be identified quickly and treated.
Even though helpful, BBT isn’t the most effective way of predicting the time from intercourse to conception. A woman’s fertility is at maximum two days prior to the ovulation and on the day of the ovulation. The BBT shows this change only 12-24 hours after this. The lifespan of the egg is just one day and therefore it might get too late before the BBT shows that there is an opportunity to conceive.
Robert L. Barbieri, M.D, at Harvard Medical School says that the couples who are trying to conceive should have sex every other day, at least, 3-4 days before the anticipated ovulation. With the help of BBT and ovulation predictor-kits, many women are able to exactly find out their most fertile day at home.
BBT helps in predicting ovulation because a woman’s temperature lies between 96 and 99 °F when she is not ovulating. Once the egg is released the temperature rises by half a degree in most of the women. This is due to the hormone progesterone which is secreted in the ovary which heats things up after ovulation so you can do Ovulation Test . This increase in temperature will be visible until the menstruation. In case a woman gets pregnant the temperature will remain high until the first trimester.
With the help of BBT, it becomes easier to detect fertility-threatening problems like luteal phase defect. In order to measure the minuscule spike in temperature, one needs to get a special basal thermometer. The thermometer looks like a normal fever thermometer but has a higher degree of accuracy (1/10th of a degree instead of 2/10th). So, in case you are trying to create a BBT chart talk to your ob-gyn to find out which one will be the proper option for you, digital one or the mercury one.