Management of neonates of diabetic mothers

The potential complications affecting the conceptus of the diabetic woman have been identified for centuries and include a multitude of problems from macrosomia/IUGR, birth asphyxia, RDS, hypoglycaemia, hypocalcaemia, polycythaemia, hyperbilirrubinaemia, heart failure and cardiomyopathy, renal vein thrombosis, etc., and these babies still require a higher rate ot admission to neonatal intensive care units posing a considerable medical and financial burden. 
Respiratory distress syndrome (RDS) due to hyaline membrane disease (HMD) is common in the infant of the diabetic mother (IDM) and is due to either inhibited or decreased lung surfactant. RDS may also be due to transient lung adaptation, a condition often associated with caesarian section and birth asphyxia, both common in diabetic pregnancies. Although the respiratory distress is often managed with O2 supplementation alone, on occasions it may require assisted ventilation (CPAP/IPPV). In addition hypoglycaemia and polycythaemia may also play a further role in the development of RDS and if the PCV is above 65-70%, with or without hyperviscosity symptoms, it may require a modified, partial, exchange transfusion to enhance respiratory function, to prevent neurological symptoms and the risk of renal vein thrombosis.
Neonatal hypoglycaemia remains controversial. Methodological problems of glucose measurement make for different definitions. Whether or not assymptomatic hypoglycaemia is less damaging than when coupled with symptoms and whether the neonate can utilize any other alternative substrates all add to the problem. Given that the sustained hyperinsulinism will make compensatory mechanisms of mobilising other fuels quite unlikely in these babies, it is recommended that blood levels should be kept in the range of >/= 2.6 mmol/1 regardless of gestational and postnatal age by promoting early enteral feeds and/or intravenous glucose if feeds are not tolerated. Glucagon administration may exceptionally be needed to promote glucose release from glycogen storages as well as to increase hepatic acids oxidation.
The whole spectrum of neonatal problems and complications can primarily be attributed to excessive maternal transferral of glucose to the fetus inducing fetal hyperglycaemia, fscell hyperplasia and sustained fetal hyperinsulinism. Therefore, the management of an IDM should start well in advance, from before conception, throughout pregnancy and delivery, with a tight metabolic control if the immediate neonatal complications are to be avoided. Moreover, in recent years it has been put forward that many adult cardiovascular disorders, as well as type 1 and 2 diabetes, may have a fetal origin in a hostile metabolic environment, placing even greater importance upon the need for good antenatal care.