The basal body temperature of the body is the temperature that it attains during the period of rest. This is usually the lowest temperature of the body. This temperature is usually taken immediately before a person wakes up and engages in physical activity of any kind. Even though the temperature which is measured immediately after waking up is considered the basal body temperature, in reality it is only the closest approximation of the basal body temperature. The actual basal body temperature is much lower than the one measured.
The temperatures vary in men and women. When a woman is ovulating, her body temperature increases one quarter to one half of a centigrade. The period of ovulation is often measured by measuring the temperature of the body. This tendency of women is known as biphasic pattern. For increasing fertility awareness, this biphasic pattern is charted and monitored.
Right before the ovulation begins, the amount of estrogen in the blood is high, because of which the temperature of the body remains low. However, during the period of ovulation, the level of progesterone in blood increases. This causes a sudden increase in the temperature, which is maintained till the time the levels of progesterone recede and normalize.
If during the period of ovulation, fertilization doesn’t take place, the corpus luteum begins to disintegrate, the levels of progesterone reduce, and the temperature of the body also falls. If fertilization occurs, the corpus luteum functions throughout the first trimester and the basal body temperature remains higher.
Tracking the basal body temperature can be beneficial in keeping a track of both ovulation and pregnancy. If you have tracked your basal body temperature, you will be able to estimate the gestational age more accurately. The basal body temperature can be easily charted and this is also helpful in determining post ovulatory infertility. However, it is not advised to use the basal body temperature for predicting ovulation.
Thermometers can be used to take the measurements. However, normal fever thermometers are not of much use when it comes to measuring basal body temperatures. There are special thermometers which have been especially created for measuring the basal body temperature. These are sensitive digital thermometers that give an accuracy of even 0.1 °F. Apart from these, special fertility monitors can also be used which record and interpret basal body temperatures in order to chart the fertile periods of the menstrual cycle.
Submitted by M T on January 14, 2010 at 12:28