Does your BBT stay the same if you are pregnant?

Typically, a pregnant person's basal body temperature (BBT) remains elevated after ovulation, staying above the cover line throughout the luteal phase. This sustained high temperature is one of the early signs of pregnancy and can be observed on a BBT chart.

During the menstrual cycle, BBT usually follows a biphasic pattern. In the follicular phase (before ovulation), BBT is generally lower. After ovulation, progesterone is released, causing a slight increase in BBT, which is referred to as the thermal shift or temperature rise. This elevated temperature typically stays above the cover line (a horizontal line drawn above the highest temperatures from the first half of the cycle) until menstruation begins if pregnancy does not occur.

If pregnancy occurs, the corpus luteum (the structure that forms from the follicle after ovulation) continues to produce progesterone, which maintains the elevated BBT. The high progesterone levels during early pregnancy help support the thickening of the uterine lining and the implantation of the fertilized egg. As pregnancy progresses, the placenta takes over the production of progesterone, and BBT remains elevated throughout the first trimester and often beyond.

However, it's worth noting that BBT charts can vary from person to person, and not all pregnant individuals experience the same exact temperature patterns. Some may observe subtle variations in their BBT during pregnancy, while others may have a more consistent elevated temperature. Therefore, it's important to use BBT charting in conjunction with other signs and symptoms of pregnancy and consult a healthcare professional for accurate confirmation of pregnancy.