Relationships between fetal growth and maternal body mass indices, plasma glucose level, and plasma insulin level in Japanese women with mildly impaired glucose tolerance

Aim: To identify variables which are strongly associated with fetal growth. Material and Methods: The study subjects were 203 Japanese women who had a plasma glucose level >= 140 mg/dL (7.8 mmol/L) on a 50-g glucose challenge test but were normoglycemic when challenged with a 75-g oral glucose tolerance test (GTT) according to the criteria previously used in Japan. All the subjects subsequently gave birth to singleton infants. The correlations between the standard deviation for birthweight (birthweight SD) and 15 other variables, including the maternal body mass index (BMI), plasma levels of glucose and insulin on the GTT, and various indices calculated using data from the GTT, were then examined. Univariate and multivariate regression analyses were performed. Results: Univariate analyses revealed significant correlations between the birthweight SD and the fasting plasma glucose level (P = 0.0063), the pre-pregnancy BMI (P = 0.0001), and the BMI at delivery (P < 0.0001). Only the BMI at delivery remained as a significant factor that was independently correlated with the birthweight SD after a multivariate regression analysis. Conclusion: The suppression of maternal weight gain, rather than the suppression of the plasma glucose level, may be effective for avoiding infants with overgrowth among Japanese women with mildly impaired glucose tolerance.