Water and Pregnancy: How Much to Drink (and Why!)

I knew I should have been drinking more water, but I didn't want to slow down my family with frequent bathroom breaks. After all, I was finally over the nausea of my first trimester and enjoying the exuberance of the second trimester when I went to Disneyland for the first time. And in the second day of mouse ears, log rides, and amusement park fare, I began experiencing frequent contractions. I knew they must be Braxton-Hicks—and therefore normal—but the pains wouldn't go away unless I lay down.

For the rest of my vacation I was flat on my back in a hotel room with the Greatest Place on Earth just next door. When I returned home, my OB-GYN explained that my contractions were likely due to dehydration. Taking better care of myself and drinking more could have saved my vacation.

Drinking an adequate amount of water is especially important when you're pregnant. From your increased blood supply to the baby's amniotic fluid, water is essential to you and your baby.

Bodies and Water

Water plays an important role in a variety of body functions. It helps nutrients reach your cells, aids in digestion, removes toxins from your body, even regulates your body temperature—water is not only necessary but vital. In fact, 55 to 65 percent of your body weight is from water, according to Dr. Joel Fuhrman, MD, a family physician specializing in nutritional medicine.

Doctors recommend that during pregnancy you drink eight eight- to 12-ounce glasses of water a day. Dr. Fuhrman points out that "80 ounces of water is an appropriate goal to strive for, but [if you eat a healthy diet] 40 ounces of water will be sufficient because you will be getting lots of water from high-water content produce such as fruits, vegetable soups, and stews." Dr. Furhman points out that the American diet can be sodium-heavy and suggests focusing on water-rich foods to reach your recommended daily dose of H2O.

Water in Pregnancy

"Typically, your body is composed of about five liters of water," says Dr. Mira Aubuchon, MD, an assistant professor in the Department of Obstetrics and Gynecology at the University of Cincinnati College of Medicine. "During your pregnancy that typically goes up to at least six liters. Most of the increase is from blood volume—blood is composed mostly of water."

Increased blood volume carries nutrients to your developing baby and then whisks waste out. Your body will naturally retain more fluid to adequately supply your blood—and as your baby grows, to replenish amniotic fluid, explains Dr. Aubuchon. And according to Pregnancy, Childbirth, and the Newborn: The Complete Guide, by Penny Simkin, "Toward the end of the pregnancy, your baby is immersed in about one quart of amniotic fluid, which is replaced every three hours."