When you're pregnant, hormonal shifts and metabolic changes—not to mention the 20 or 30 extra pounds you're lugging around—can make you feel as if someone's turning up the heat. And that means the steamy summer months are no picnic.
"Essentially, a pregnant woman acts as a radiator for her baby," says Patrick Duff, M.D., a professor of obstetrics at the University of Florida at Gainesville. As the fetus grows, it generates heat, and the only way to vent that excess energy is through your cardiovascular system. As a result, your blood volume and metabolic rate rise, which can make you feel uncomfortably toasty.
Aside from feeling like the warmest (and sweatiest) person around, this means you're at risk for heat-related problems, such as dizziness, weakness, and fainting. All may be symptoms of dehydration, which is more likely when you spend time in the sun. Light-headedness, excessive fatigue, and dark, scant urine are warning signs that you're drying out. If left untreated, dehydration can even lead to preterm labor.
Overheating early in pregnancy may also put your developing baby at risk. "Exposure to extreme heat in the third or fourth week after conception can disrupt the closure of the neural tube, causing spina bifida or other birth defects," Duff says. That's why hot tubs and saunas are off-limits if you're trying to conceive or think you may be pregnant.
Of course, you can't park yourself in front of an air conditioner all season. Although it's a good idea to find a cool sanctuary on the hottest days, there are ways to stay comfortable during the summer:
Dress cool. Wear light-colored, loose-fitting apparel made of natural fibers, and layer clothing so that you can adapt quickly when the temperature changes.
Drink up. Six to eight glasses of liquid may not do it on really hot days. "It's not enough to quench your thirst," Duff says. "In general, drink more than you normally would." The color of your urine is a good hydration indicator: If it's almost clear, you're getting enough liquid.
Play sensibly. Although exertion can raise your temperature, if you're fit and your pregnancy isn't considered high-risk, you can join in a casual game of Frisbee or volleyball with little worry, according to experts. But be vigilant about staying cool and getting enough liquid. "Always prehydrate," says Jennifer Klau, a West Hartford, CT, personal trainer. "Drink 16 ounces of water or juice an hour or so before exerting yourself." Take a few swigs every 15 minutes while you play, and guzzle another 16 ounces after you call it quits. Most important, take a breather if you're getting too hot.
Take it easy. As tempted as you may be to make the most of the season, remember that some of the best kinds of summer fun involve doing nothing at all. So find some shade, crack open that book you've been meaning to read, and let someone else tend to the gardening. You're already perspiring for two, after all.