Neonatal macrosomia in maternal diabetes.

In order to determine the effect of maternal diabetes on the somatic growth of the rat fetus and to elucidate mechanisms underlying the control of fetal growth, concentrations of DNA and proteins and DNA polymerase-alpha activities in neonates were examined. The maternal status was classified as normal (no urinary glucose excretion), mildly diabetic (0.01-0.99 g/day urinary glucose), and severely diabetic (1.00 g/day or more urinary glucose). The total DNA contents in mg/neonate were 26.8 +/- 2.2 (mean +/- SEM), 31.3 +/- 2.5, and 29.4 +/- 2.7 for neonates from normal, mildly diabetic and severely diabetic mothers, respectively. The DNA polymerase activities in (cpm/g neonate) X 10(-3) for the same groups of neonates were 432 +/- 58, 1,008 +/- 74, and 888 +/- 118, respectively. These results indicate that the neonatal macrosomia disappears as the severity of maternal diabetes increases. Furthermore, DNA polymerase is one of possible biochemical sites through which macrosomia is manifested in diabetic pregnancies.