Diabetic pregnancy. The effect of genetic susceptibility for diabetes on fetal weight.
Since macrosomic infants of diabetic mothers tend to remain obese throughout their lives, and obesity and heredity are factors predisposing to Type II diabetes, it can be hypothesized that infants who are going to develop diabetes later in life are more likely to be macrosomic at birth than those who are not going to develop diabetes as adults. This hypothesis was tested, using the c57/KsJdb+/+m mouse animal model of gestational diabetes. This animal is frankly diabetic in the homozygous diabetic form. In the heterozygous form, it develops gestational diabetes, and in the homozygous normal form, it is normal. The pups of heterozygous males and females that were bred were weighed, classified by sex, and identified. At 4 weeks of age, the genetic makeup of the pups was determined. From 37 litters, 140 pups were born and raised to weaning age. Multiple regression analysis of the data revealed that the homozygous diabetic pups weighed most at birth; the heterozygous gestationally diabetic pups weighed less, and the homozygous normal pups weighed the least. All comparisons of these groups were statistically significant. Sex and interlitter variation also were found to be significant factors determining birthweight. Controlling for sex and interlitter variation did not change the significance of the effect of the genetic tendency for diabetes on birthweight. This study indicates that in Type II diabetes, neonatal macrosomia in part may be determined by the genetic or congenital susceptibility to develop diabetes in the future.
D000818:Animals; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D004195:Disease Models, Animal; D005260:Female; D005320:Fetal Macrosomia / Q000209:etiology*; D006720:Homozygote; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000235:genetics*; D012737:Sex Factors