Can you harm your baby if you are dehydrated during pregnancy?
It is so easy to get dehydrated in pregnancy! Your baby makes extra heat that has to be eliminated through your body—so you are likely to sweat more than normal. Plus you may not feel well enough to drink as much as your body wants. So pregnant moms may have less fluids going in, and more going out.
By far the greatest problem with dehydration is its effects on the mom, rather than on the baby. Dehydration is uncomfortable, especially in pregnancy. The mom may feel lightheaded or even actually faint. Her heart may pound, or nausea can develop (a double whammy if she is dehydrated because of morning sickness!).
Later in pregnancy, dehydration can be an issue for the baby as well. Many moms-to-be notice uterine contractions when they are dehydrated. Severe dehydration in the late second or in the third trimester may buy an admission to the hospital for preterm labor.
Many pregnancy resources say to drink a certain amount of water but that isn't based on anything scientific. It is important to get the amount of fluids that your body needs—in whatever way that can be done. The best approach is to drink liberally, and respond to thirst. For some moms, water just doesn't go down well, and they need sports drinks or diluted juices.
Signs of dehydration like severe thirst and dizziness should be taken seriously. If a mom can't catch back up with oral hydration on her own she should seek medical assistance.