Moderate maternal vitamin A deficiency affects perinatal organ growth and development in rats

Vitamin A deficiency during pregnancy is associated with detrimental effect s in the offspring. We have developed a rat model to examine specific effec ts of maternal vitamin A status on perinatal growth and development. A tota l of 54 female rats were fed a vitamin A-free (VAF), -marginal (VAM) or -su fficient (VAS) diet from weaning until mating (at 7 weeks) and throughout p regnancy. Half of the rats in each group were injected with a single large dose of vitamin A on day 10 of pregnancy. Fetal and neonatal samples were t aken on day 20 of pregnancy and the day of birth respectively. Maternal pla sma retinol concentrations on day 20 and at birth were 50 % and 30 % lower in the VAF and VAM when compared to the VAS group. Fetal weight and surviva l did not differ between groups although placental : fetal ratio was higher in the VAF group than in the VAS group (0.195 (se 0.005) v. 0.175 (se 0.00 4), P < 0.05). Rats fed the VAF diet gave birth at 23.5 d, an average of 1 d later than the other groups, and had lower number of live neonates at bir th. Fetal liver, heart and lung weights relative to total body weight were lower in the VAF group and had altered growth trajectories. In neonates, on ly the relative lung weight was reduced. In addition, an increased protein : DNA ratio indicated hypertrophy in fetal kidneys. Vitamin A injection had no additional effect on length of gestation and fetal or neonatal number. However, injection increased relative fetal organ weights in the VAF group but did not alter the effects of vitamin A deficiency in the neonate. These data suggest that chronic vitamin A deficiency during pregnancy compromise s liver, heart and kidney and impairs lung growth and development during th e last few days of gestation and reduces number of live neonates at birth.