Relationship of neonatal body composition to maternal glucose control in women with gestational diabetes mellitus

Abstract

OBJECTIVE: To determine whether neonatal fat mass, which may be a better estimate of fetal overgrowth, is correlated with maternal fasting, preprandial and/or postprandial glucose values in women with gestational diabetes mellitus (GDM). STUDY DESIGN: Women with GDM and no other medical or obstetric problems, and their infants, were the subjects of this study. Portable reflectance meters were used by all participants for self-monitoring of blood glucose levels. Average fasting, preprandial, 2-h postprandial and bedtime glucose values were determined for each subject. Neonatal body composition was obtained by total body electric conductivity and/or anthropometric measurements within 48 h after delivery. RESULTS: Eighteen women with their infants participated in this study. The age (mean +/- SD) of the mothers was 28.0 +/- 5.7 years. Nine were treated with diet and nine with diet and insulin. An average of 40 fasting (84 +/- 13 mg/dl), 50 preprandial (87 +/- 14 mg/dl), 80 2-h postprandial (106 +/- 19 mg/dl) and 17 bedtime (104 +/- 19 mg/dl) glucose values were obtained from each subject. The average gestational age of the infants at birth was 38.3 +/- 1.3 weeks with a mean weight of 3,356 +/- 526 g. Three infants were > 4 kg and seven infants were > 90th centile for gestational age. The strongest correlation with neonatal fat mass was maternal fasting glucose level (r = 0.71, p < 0.01). Neonatal fat mass was not found to be significantly correlated with any other mean glucose value. Additionally, the infant's per cent body fat (r = 0.71, p < 0.01), sum of skinfold thicknesses (r = 0.70, p < 0.01), fat-free mass (r = 0.50, p < 0.05), and weight (r = 0.61, p < 0.01) were also found to be correlated with maternal fasting glucose level. No other maternal glucose measurements were correlated with either birth weight or estimates of fat free mass. CONCLUSION: Maternal fasting glucose levels correlated best with neonatal fat mass and other estimates of neonatal body composition.