Fetal growth requires lots of water, not to mention to sudden increase in fluid retention and blood volume. During pregnancy, women should drink at least 64 ounces of water in addition to other beverages to keep their skin healthy and lubricated. The skin of the lips is no different; dehydration can cause a nasty case of chapped lips.
Treating chapped lips requires three coordinated changes. The first is drinking more water. More water combats chapped lips from the inside of the body. Externally, pregnant women can choose to use ChapStick or other forms of lubricating lip treatment to instantly increase surface moisture. The third step is one of the most important: stop licking your lips and repeat steps one and two.