Dehydration is an insufficient amount of water in the body. Either insufficient drinking or excessive water loss from the body can lead to dehydration.
Dehydration can be a mild nuisance or a life-threatening condition for both the mother and the baby.
A pregnant woman can become dehydrated from the same reasons as anyone other. Main causes include:
Morning sickness can prevent a woman to eat and drink enough. In severe morning sickness called hyperemesis gravidarum, a woman can additionally lose a lot of fluid by repeated vomiting and is therefore at high risk for severe dehydration that requires admission to hospital and intravenous fluid replacement.
Symptoms: Thirst (not always), slight anxiety, slightly decreased frequency of urination Signs: Slightly increased heart rate.
Signs: Increased heart rate, prolonged skin recoil after pinch and release (up to 2 seconds).
Severe dehydration can affect the baby [1,2,4]:
According to the U.S. Institute of Medicine (IOM), the Adequate Intake (AI) for water during pregnancy is 3 liters 5. Adequate intake means amount of water from both foods and beverages that would provide adequate hydration for most pregnant women. But a woman may need less or more than this amount of depending on how much of water she loses. You probably drink enough when:
When you are mildly or moderately dehydrated you can replace the lost fluid by drinking more water. For every kilogram of lost weight you drink about 1.5 liters fluid (to cover the missing amount of water and the current loses from the urine).
It is not clear if caffeine is harmful for the developing baby, but most doctors advise against drinking caffeinated beverages (regular coffee, tea, cola, energy drinks) during pregnancy.
Nausea and vomiting are the main causes of severe dehydration in pregnancy. Severe dehydration is usually treated in a hospital with infusion of fluids, such as 0.9% solution of sodium chloride into a vein (intravenous infusion). Treatment of nausea and vomiting may be necessary at the same time.
Ketones in the urine of pregnant women is usually a sign of low carbohydrate diet or fasting due to nausea, or gestational diabetes. Dehydration can cause false positive results for urinary ketones .