It is very common for a woman's body temperature to change during pregnancy. During pregnancy, a woman's metabolism speeds up, which causes her body to create additional heat. To help to cope with this, a woman's body temperature actually decreases over the course of her pregnancy, to keep her base temperature from rising as her metabolic rate rises. The rise in metabolic rate is also part of the reason that she will need to take in extra calories during pregnancy.
In addition, the fluctuation of hormones can create hot flashes or other temperature changes during pregnancy. It is not uncommon for a pregnant woman to experience hot flashes, either during the daytime or the nighttime.
at 8:05 PM on Aug. 9, 2009