What to Know About Hot Flashes in the First Month of Pregnancy

Hot flashes are the bane of many a woman's existence. Typically, this flash of sweat is seen in peri-menopausal and menopausal woman — and having one can cause you to alternatively fling off extra bed coverings and then huddle under them just minutes later.

But while hot flashes are commonly associated with menopause, they're also experienced by women during pregnancy — the result of hormonal changes and a few other factors. However, experiencing these flashes early in pregnancy, during the first month, seems to be less common than later on.

In fact, hot flashes occur more frequently late in pregnancy rather than the first trimester and increase even more in the postpartum period. Indeed, a December 2013 study in the journal Fertility and Sterility found that while night sweats varied among the 430 pregnant women participating, hot flashes peaked at week 30 and later on during the second week postpartum.

Why Pregnant Women Get Hot Flashes

If you find yourself fanning your face with anything you can get your hands on, you're not alone. A sweaty pregnancy is rather common, per the study in Fertility and Sterility. Researchers found that 35 percent of women reported night sweats and hot flashes during pregnancy, and nearly as many experienced the same kind of heat after the baby was born.

While changing hormones can cause hot flashes, they're not the only cause. Hormones such as progesterone raise your body temperature. Nausea can cause feelings of heat and sweating or cold sweats. And that tiny baby growing inside you can also generate heat, according to Johns Hopkins Medicine.

Some women could be experiencing a decreased tolerance of temperature fluctuations due to hormonal changes in pregnancy, confirms Nishath Ali, MD, an assistant professor of obstetrics and gynecology at Baylor College of Medicine. "But hot flashes could also be related to other medical conditions, including serious things like cardiac dysfunction, so it is important to discuss them with your doctor," she adds. The Mayo Clinic backs this up, noting that hot flashes may indicate an underlying condition such as heart disease or even breast cancer.

Hot Flashes in Early Pregnancy

A young woman with a hot flash cooling off in front of a fan

Early Signs of Implantation Pregnancy

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Hot flashes may occur even before you know you're pregnant, around the time that the embryo implants in the uterine wall. Implantation normally occurs between eight to 10 days after ovulation, says Amos Grunebaum, MD, an ob-gyn at Weill Cornell Medical Center.

The hormone progesterone, produced by the corpus luteum (the remnant of the follicle that contained an egg), rises after ovulation. Progesterone continues to rise after implantation of the embryo as the production of human chorionic gonadotropin, or hCG, signals the corpus luteum to keep producing progesterone. And, as noted before, progesterone can raise your body temperature.

Hot flashes may make you feel uncomfortable, but keep in mind that the flashes themselves are not likely to harm the fetus, says Dr. Ali.


Make sure what you're experiencing is hot flashes and not an actual fever; call your doctor if your temperature rises above 100 degrees.

How to Deal With Hot Flashes

You can't turn off your hormones when you're pregnant, but you can use external methods to help keep the heat down.

  • Wear layers so you can dress up or down, depending on what your internal thermometer is telling you at the moment. 
  • Pick fabrics that breathe rather than man-made fabrics that tend to hold in more heat. 
  • Staying well hydrated is also a smart idea, as a higher body temperature may cause you to lose more fluid. 
  • Discuss symptoms with your doctor to identify the cause. "Depending on the cause, hot flashes might be managed with the avoidance of triggers like overheating, spicy foods and outside stressors," says Dr. Ali. And women need to make sure there's not an underlying medical cause like an issue with blood pressure, blood sugars, or thyroid dysfunction, she adds.