There is no set amount. Drink until your urine is a pale yellow. That way you’ll know you are drinking enough water.
Most pregnant women have been told some number when it comes to how many glasses of water they should be drinking on a daily basis. The thought behind this is that it is easier for pregnant women to become dehydrated, and dehydration can make you more prone to contractions or urinary tract infections, among other things.
Setting an exact number of ounces or glasses isn’t the best way to know you are getting enough water, though. If you drink enough so that your urine is a pale yellow color, then you know you are drinking enough water. If your urine is very dark, you need to drink more. If your urine is almost clear, you are probably overdoing it and can cut back some.