Parameters of brain development were studied in near term guinea-pigs in relation to
fetal weight and maternal
glucose tolerance during normal gestation. Seven litters (22 fetuses) were studied.
Fetal weight ranged from 43 to 94 g (119% variability) and the maternal
glucose index (sum of the 7 serum
glucose levels during the oral
glucose tolerance tests) from 921 to 1,528 mg/dl (66% variability). The weights of the cerebrum and cerebellum were less affected by changes of
fetal weight compared to other fetal organs. Significant correlations were observed between the maternal
glucose index and brain cell number (
DNA) and myelination (cerebroside-
sulfatide). These variables did not correlate with
fetal weight. Liver
weight (% fetal weight) and cell number also correlated with the maternal
glucose index. It is speculated that the amount of
glucose available to the brain could be responsible for the relative protection of the brain to
fetal malnutrition and also for the link between maternal
glucose index and parameters of fetal brain development.