Drinking plenty of fluids is more important now than at any other time in your pregnancy. Staying fully hydrated can help prevent uterine tightening, headaches, constipation, and dizziness. If you're well hydrated when you go into labor, you'll have more stamina than you would if your body lacked fluids. And remember that your baby needs water for her body and the fluid-filled amniotic sac where she lives. If you're hydrated, she will be too.
Eight glasses (64 ounces total) of water a day will keep you hydrated. Drink a few extra glasses if you exercise or if the weather is warm and you're perspiring heavily. If you're drinking enough water, your urine will be nearly clear; if you're not, it will be deep yellow.
Water is the best way to hydrate, but other fluids count in your daily tally, including milk, fruit juice, and decaffeinated coffee or tea. Most fruits and vegetables contain water. Tomatoes, for example, are 94 percent water by weight, and apples are 85 percent.