Early post-natal growth of large-for-dates babies of non-diabetic mothers is influenced by maternal glucose metabolism.

Growth of weight, length, head circumference and skinfold thickness (subscapular and triceps) from birth to 6 months in 53 large-for-dates (LFD) Chinese babies weighing greater than 4.0 kg at term and born to non-diabetic mothers was investigated and correlated with biochemical indices of maternal glucose tolerance at birth: glycosylated haemoglobin (HbA1), serum corrected fructosamine and the area under the oral glucose (50 g) tolerance (OGTT) curve. Growth in all physical dimensions, especially weight, showed a downward shift towards a reference mean. These changes in relative size were caused by slower growth velocities. None of the mothers had abnormally high concentrations of HbA1 or fructosamine nor an abnormal OGTT. However, weight velocities did show small but significant correlations with fructosamine (r = -0.42), and OGTT area units (r = 0.39) but not with HbA1. For some macrosomic babies born to apparently normal mothers, birth is seen to interrupt a process operating in prenatal life that accelerates growth. Covert abnormalities of maternal glucose homeostasis could explain this. Abnormal glucose tolerance during pregnancy might therefore be viewed as a continuum extending from (i) its maximum expression, the frankly diabetic state, through (ii) gestational diabetes to (iii) the mother who has no biochemically evident abnormality of glucose homeostasis but who has sufficient alteration to modify fetal growth. Post-natal growth of LFD babies is additional information which, when taken along with other markers of maternal glucose tolerance, might help to identify the mother at later perinatal risk.