Expert answer: Jill Stovsky, exercise physiologist and dietitian
You should drink at least six to eight 8-ounce glasses per day (48 to 64 fluid ounces) plus one 8-ounce cup for each hour of light activity. Juices can contribute to your fluid intake, but keep in mind that they can also provide a lot of extra calories.
This may surprise you, but you can also count coffee and tea (whether caffeinated or not) as part of your fluid intake. Experts used to caution that caffeinated beverages don't count because caffeine is a diuretic (makes you urinate more and lose water). But it's been found that the loss of water is minimal.
Water plays many vital roles in a healthy pregnancy. Think of water as your body's transportation system – it carries nutrients through your blood to your baby. Water also helps prevent bladder infections, which are common during pregnancy. If you drink enough water, your urine will stay diluted, reducing your risk of infection.
Water can also stop constipation and help prevent hemorrhoids. Although it may seem counterintuitive, the more water you drink during pregnancy, the less water your body will retain. Also, drinking enough water prevents dehydration. This is especially important in the third trimester when dehydration can actually cause contractions that can trigger preterm labor.
If you just don't like the taste of water, try adding a wedge of lemon or lime, or a little juice for additional flavor. If you're not sure how much water you drink each day, fill a 64-ounce container and try to finish it by the end of the day.