What degree of maternal metabolic control in women with type 1 diabetes is associated with normal body size and proportions in full-term infants?

OBJECTIVE: To assess what degree of maternal metabolic control in women with type 1 diabetes is associated with normal fetal growth and results in normal neonatal body proportions in a group of full-term infants. RESEARCH DESIGN AND METHODS: We investigated the anthropometric characteristics of 98 full-term singleton infants born to 98 Caucasian women with type 1 diabetes enrolled within 12 weeks of gestation. The type 1 diabetic mother-infant pairs were divided into three groups on the basis of the daily glucose levels reached during the second and third trimesters of pregnancy (group 1: 37 mother-infant pairs with an average daily glucose level during the second and third trimesters of < or =95 mg/dl; group 2: 37 mother-infant pairs with an average daily glucose level during the second trimester of >95 mg/dl and during the third trimester of < or =95 mg/dl; group 3: 24 mother-infant pairs with an average daily glucose level during the second and third trimesters of >95 mg/dl; control group: 1,415 Caucasian mother-infant pairs with full-term singleton pregnancies and normal glucose challenge test screened for gestational diabetes.
RESULTS: Infants of diabetic mothers in group 1 were similar to those of the control group in birth weight and in other anthropometric parameters. In contrast, offspring of diabetic mothers of groups 2 and 3 showed an increased incidence of large-for-gestational-age infants, significantly greater means of ponderal index and thoracic circumferences, and significantly smaller cranial/thoracic circumference ratios with respect to the control group.
CONCLUSIONS: The results of our study suggest that, in diabetic pregnancies, only overall daily glucose values < or =95 mg/dl throughout the second and third trimesters can avoid alterations in fetal growth.