Low sodium intake is associated with low birth weight and size only when given in the second half of gestation

Abstract

This study examined the effects of maternal low sodium intake during different periods of pregnancy on dams and male (M) and female (F) offspring. Methods: Female Wistar rats (n= 6 - 8/group) were fed low (LS - 0.15%) or normal (NS - 1.3% NaCl) sodium diet since the 1st day of gestation until delivery or LS during the 1st (LS10) or 2nd half of gestation (LS20). Results: (mean±SEM, p< 0.05): Maternal body weight (g) was lower in LS and LS20 than in NS and LS10 at the 3rd week of gestation (LS = 380±8.1; LS20 = 406±13.2; NS = 435±6.1, LS10 = 461±12.9). No difference was found in water and food intake among the groups. Also, no differences were observed in the litter size among experimental groups and no correlation betweenthe number of pups and maternal body weight at the 3rd week of gestation. At birth, body weight (g, n=14 to 27/group) (M: NS = 6.5±0.1, LS = 5.5±0.1, LS10 = 6.1±0.1, LS20 =4.8±0.1,F:NS = 6.1±0.2, LS = 5.2±0.1, LS10 = 5.6±0.1, LS20 = 4.1±0.1) and naso-anal length (cm, n=14 to 27) (M: NS = 5.1±0.02, LS = 4.9±0.03, LS10 = 5.0±0.03, LS20 = 4.6±0.03, F: NS =4.9±0.05,LS = 4.8±0.04, LS10 = 4.9±0.03, LS20 = 4.4±0.03) were lower in LS and LS20 than in NS offspring. Conclusion: Although maternal dietary intake was not influenced by dietary sodium content, maternal low sodium diet during the second half of gestation induced lower birth weight and size.