[The following is adapted (and in some cases quoted) from What Every Pregnant Woman Should Know by Gail Sforza Brewer and Thomas Brewer, M.D., Chapter 4.]
Salt is a vital nutrient. No woman, expectant or otherwise, can live without it. Neither can the unborn baby, who receives sodium from his mother’s blood stream, through the placenta. Sodium requirements vary widely depending on activity level, environmental conditions, personal health, and many more factors. Pregnancy is one condition where the body actually requires MORE salt in order to remain healthy.
Each person has many finely tuned mechanisms that work in the body to preserve the appropriate concentration of sodium in the tissues and in the bloodstream. In normal pregnancy, the mother’s blood volume must expand by more than 40% to meet the metabolic demands of the placenta. Salt is a chief element in maintaining this dramatically expanded blood volume. Salt causes the body to retain fluid, which, under normal conditions, is retained in the bloodstream for use in placental perfusion.
Salt restriction during pregnancy limits the normal expansion of the blood volume, with disastrous consequences. Depending on the degree of sodium restriction and the subsequent blood volume limitation the placenta may:
- grow slowly, or not at all,
- develop areas of dead tissue (infarcts) that cannot function,
- be unable to accomplish the transfer of nutrients to the baby,
- even begin to separate from the wall of the uterus, causing hemorrhage and cutting off the baby’s oxygen supply.
Under these conditions, the baby’s growth, development and even life are imperiled.
Cutting out salt frequently leads to an inadequate diet in other areas as well. Foods such as eggs, milk, cheese and salty meat products are often on the list of restricted foods for a low-salt diet. These foods are sources of essential high-quality protein, necessary for baby’s growth, and for prevention of toxemia. It may also mean reduced food intake overall, as food is no longer quite as palatable without salt. Inadequate calorie consumption leads to the body using protein for fuel…protein needed for the baby’s growth and development.
Some women live and/or work in conditions that cause their bodies to lose more sodium than is healthful (hot climate, “sweaty” work, aerobic exercise, etc.), and thus boost the body’s sodium need. If the mother does not take in more, her depletion will activate temporary sodium-conserving mechanisms in the kidneys and adrenal glands. If salt deprivation continues, these organs can become exhausted, and show signs of degenerative disease.