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

Dehydration and Preterm Labor

While researchers are still not sure of the exact body mechanism that triggers contractions, there seems to be a link between dehydration and preterm labor. "But whether these contractions [from dehydration] translate to a full-term birth is not really known," says Dr. Aubuchon.

One thought is that "dehydration can promote the release of antidiuretic hormone from the kidney to preserve water excretion, which in turn promotes oxytocin, leading to premature contractions," says Dr. Fuhrman. These contractions can be an uncomfortable reminder that you need keep your body hydrated.

Dehydration and Preeclampsia

You may notice your healthcare provider checking your face and hands for swelling during routine office visits. Abnormal swelling (or edema) may be a sign that you are experiencing pregnancy-induced hypertension or preeclampsia. Although doctors are still unclear as to the precise reason why some pregnant women experience hypertension, Dr. Aubuchon says two symptoms to watch for are high blood pressure and dehydration.

Dr. Aubuchon also explains that there is no connection between preeclampsia and not drinking adequate amounts of water. Rather, retaining fluid and becoming easily dehydrated are symptoms of preeclampsia.

Questionable Water

You need water to stay healthy during your pregnancy, yet studies offer varying views on just where that water should come from.

"Yes, there are chlorinated by-products in tap water that in some small studies have had some negative effects [on the health of the baby], yet other studies indicate no effect," says Dr. Aubuchon. These potentially harmful by-products are not absorbed simply from drinking water, but can be inhaled, such as when you're in the shower, or through skin contact, like when you wash your hands. Dr. Aubuchon says any serious health risks are minimal, although the topic remains the basis for ongoing research.

Bottled water may seem like a solution to potential health risks associated with drinking chlorinated tap water, yet Dr. Aubuchon cautions that "there are fewer regulations on bottled water than there are on tap water. Several kinds of bottled waters may very well be contaminated with different [harmful substances]."

If you are concerned, Dr. Fuhrman recommends that you order distilled spring water from a water delivery service or invest in a good-quality water purification system.

Neither Dr. Aubuchon nor Dr. Fuhrman recommends drinking specialized waters, such as those enriched with vitamins. "You need to be very careful that you aren't taking any vitamins in excess," says Dr. Aubuchon. "In pregnancy, more is not necessarily better."

With so many concerns during pregnancy, you shouldn't have to worry about whether you're drinking enough. Drinking a full glass of water at mealtimes and with snacks should provide the amount of water you and your growing baby need.