Effects of exogenous vitamin C on maintenance of pregnancy in diet-restricted rats

Colony-bred four to five month old female rats (average weight 240 g, S.D. 20 g) of Sprague-Dawley origin were used to determine the effects of adding ascorbic acid to the diet of restricted fed pregnant rats on: (1) body weight gains of the dams, (2) organ weights, and (3) tissue biochemistry of the dams during gestation, and (4) fetal weights. A minimum of 20 bred females were assigned to each of the following treatments: (1) ad libitum fed plus 25 mg vitamin C (U.S.P.- crystals) administered per os daily via stomach tube attached to a 1 ml plastic syringe; (2) ad libitum fed; (3) restricted fed (15 g/day) plus 25 mg vitamin C per os daily; (4) restricted fed (15 g/day); (5) restricted fed (15 g/day) plus 12.5 mg vitamin C per os daily; (6) restricted fed (15 g/day). Females were assigned to treatment groups on the day sperm were found in the vaginal smears. Body weights were recorded on day 1 and day 22 of pregnancy (prior to sacrifice). Livers and uteri were removed from each animal and weighed, and approximately 2 ml of blood for glucose determination were taken via cardiac puncture. The placentas were freed from the fetuses and analyzed for glycogen, and the fetuses were individually weighed. Supplementing the ration with vitamin C did not effect any of the parameters studied except placental weight per fetus (P<.05). The major differences were associated with level of feeding. Maternal weight gain during pregnancy, maternal liver weights and uteri of ad libitum fed females were significantly greater (P<.001) than those of the limited fed (15 g day) females. There was no evidence that vitamin C or level of feeding affected litter size.