Intravenous glucose tolerance and plasma insulin studies in small-for-dates infants.

A study of infants who were small-for-dates is described. A proportion of them developed hypoglycaemia, and in these, intravenously administered glucose disappeared abnormally rapidly from the blood, shown by a raised kG value. Some of these infants also showed raised levels of plasma insulin. Those with the high levels of plasma insulin showed significant change in fasting `true' blood glucose, and mean maximum plasma insulin levels at the end of the first week of life. Hypoglycaemia of the newborn is probably more closely related to other factors as yet still undefined, than to changes in plasma insulin alone.