89 Hypoglycemia in Infants with Erythroblastosis Fetalis

Hyperplasia of the Islets of Langerhans is usually found in fetuses in infants who die as a result of erythroblastosis fetalis (EF) and the pancreas contains levels of insulin comparable to those found in infants of diabetic mothers (IDM). The clinical counterpart of these observations, hypoglycemia, is believed to occur rarely if at all in infants with EF. During the last 18 months we have observed hypoglycemia (< 30 mg/100 ml in term infants; < 20 mg/100 ml pre-term) in 11 infants. Borderline levels have occurred in 2 others. Five of the infants developed hypoglycemia prior to exchange transfusion (ET). Recently 16 consecutive infants with moderate to severe EF have had frequent blood glucose measurements following ET. 6 (30 %) developed symptomatic hypoglycemia with borderline values in 2 others. 9 infants had multiple measurements of blood glucose in the 3 h period following ET and 4 of these had simultaneous measurements of serum immuno active insulin. Serum insulin was elevated in all 4 infants. Glucose disappearance constants (Kt) were calculated for the first hour following ETand compared to Kt values for normals and IDM following IV glucose tolerance tests. The infants with EF who developed hypoglycemia had significantly greater Kt values than did the normals; their values approximated IDM. Because of the necessity for prompt treatment, blood glucose should be measured frequently in infants with EF both after birth and after ET. Intravenous glucose or fructose should be effective in prevention of hypoglycemia. (APS)