Women who are trying to get pregnancy to want to know as soon as possible whether they have a baby on board, and many reports experiencing a slight fever before they’ve even missed their period. Is a fever an early sign of pregnancy? The answer is more complex than a simple yes or no.
Temperature has long been used to track fertility, as Felice Gersh, M.D., OB-GYN, told Romper in an interview. Body temperature is related to hormones, which fluctuate through a woman’s menstrual cycle. It’s why basal body temperature can be used to track ovulation.
“Progesterone is produced after ovulation and results in a small temperature elevation, which is the foundation of the basal body temperature charting,” Dr. Gersh says. “Measuring one’s temperature first thing in the morning with a special basal body thermometer was commonly done for fertility evaluations prior to the development of ovulation kits, but still continues to be utilized by many women for natural fertility planning.”
The same hormone that makes it possible to track your cycle using temperature is what causes an increase in your overall body temp early on in pregnancy, Dr. Gersh adds. But it’s not to be mistaken for a true fever.
“Pregnancy results in a far greater production of progesterone and a small further increase in temperature, which can be perceived as a fever by the woman, but actually is only a normal small temperature rise,” she says.
So, while it’s not exactly a fever, a slight uptick in your body’s temperature may clue you in to the fact that your progesterone is higher than usual. But if you find yourself with symptoms of a fever, like body chills or aches and pains, be sure to visit your doctor.
“Becoming infected with a virus or bacterial agent during pregnancy can have very dire consequences, depending on the time of pregnancy and the infectious agent,” says Gersh. “It is a rarity these days due to vaccines, but infection with the virus called rubella was well known to cause serious birth defects. Parvovirus can wreak havoc in the body of the developing baby. Flu viruses as well can be very damaging.”