The effect of sodium restriction during gestation of offspring brain development in rats.

Sodium restrictive diets are today often recommended to women experiencing the normal edema of pregnancy. This study explores some effects of dietary sodium restriction, imposed during pregnancy, on reproductive performance and brain development in resultant offspring. Pregnant Sprague-Dawley rats were fed diets containing either 0.173, 0.067, 0.040, or 0.022% sodium throughout gestation. All other nutrients in the diet were fed at levels in excess of NAS-NRC requirements. At parturition, litters were trimmed to four offspring and mothers fed Purina Rat Chow throughout lactation. Twenty-one days postpartum, offspring were killed and analyses of selected parameters of brain composition made. Rats fed the 0.040 and 0.022% were killed and analyses of selected parameters of brain composition made. Rats fed the 0.040 and 0.022% sodium containing diets during pregnancy consumed less feed, gained less weight, and exhibited altered fluid consumption patterns to rats ingesting the 0.173% sodium control diet. Mothers fed the two diets containing the lowest levels of sodium also had smaller litters, fewer live births, and more stillbirths per litter than control mothers. Birth weights and the number of offspring surviving the lactation period were less in the 0.040 and 0.022% sodium treatment groups. No offspring in the 0.022% sodium diet group survived the lactation period. Brain wet weight, dry weight, cholesterol, protein, and RNA content were decreased in offspring in the 0.040% sodium diet group.