Large-for-Gestational-Age (LGA) Infant

Because of the infant’s large size, vaginal delivery may be difficult and occasionally results in birth injury Birth Injuries The forces of labor and delivery occasionally cause physical injury to the infant. The incidence of neonatal injury resulting from difficult or traumatic deliveries is decreasing due to increasing... read more , particularly including

Other complications occur when weight is > 4000 g. There is a proportional increase in morbidity and mortality due to the following:

IDMs are at risk of

Hypoglycemia Neonatal Hypoglycemia Hypoglycemia is difficult to define in neonates but is generally considered a serum glucose concentration < 40 mg/dL (< 2.2 mmol/L) in symptomatic term neonates, < 45 mg/dL (< 2... read more is very likely in the first few hours after delivery because of the state of hyperinsulinism and the sudden termination of maternal glucose when the umbilical cord is cut. Neonatal hypoglycemia can be decreased by close prenatal control of the mother’s diabetes and early frequent feedings. Blood glucose levels should be closely monitored by bedside testing from birth through the first 24 hours. Oral treatment with 40% glucose gel may be tried first, but if there is persistent hypoglycemia, parenteral IV glucose is given.

Hypocalcemia Neonatal Hypocalcemia Hypocalcemia is a total serum calcium concentration < 8 mg/dL (< 2 mmol/L) in term infants or < 7 mg/dL (< 1.75 mmol/L) in preterm infants. It is also defined as an ionized calcium... read more and hypomagnesemia Hypomagnesemia Hypomagnesemia is serum magnesium concentration < 1.8 mg/dL (< 0.70 mmol/L). Causes include inadequate magnesium intake and absorption or increased excretion due to hypercalcemia or drugs... read more may occur but are usually transient and asymptomatic. Good prenatal glycemic control decreases the risk of neonatal hypocalcemia. Hypocalcemia typically does not require treatment unless there are clinical signs of hypocalcemia or total serum calcium levels < 7 mg/dL (< 1.75 mmol/L) or ionized calcium levels < 4 mg/dL (< 1 mmol/L) in term infants. Treatment should be based on ionized calcium levels because these levels more accurately reflect available calcium. Treatment is usually given with IV supplementation of calcium gluconate. Hypomagnesemia can interfere with the secretion of parathyroid hormone, so hypocalcemia may not respond to treatment until the magnesium level is corrected.

Polycythemia Perinatal Polycythemia and Hyperviscosity Syndrome Polycythemia is an abnormal increase in red blood cell mass, defined in neonates as a venous hematocrit ≥ 65%; this increase can lead to hyperviscosity with sludging of blood within vessels... read more is slightly more common among infants of diabetic mothers. Elevated insulin levels increase fetal metabolism and thus oxygen consumption. If the placenta is unable to meet the increased oxygen demand, fetal hypoxemia occurs, triggering an increase in erythropoietin and thus hematocrit.

Hyperbilirubinemia Neonatal Hyperbilirubinemia Jaundice is a yellow discoloration of the skin and eyes caused by hyperbilirubinemia (elevated serum bilirubin concentration). The serum bilirubin level required to cause jaundice varies with... read more occurs for several reasons. IDMs often have decreased tolerance for oral feedings (particularly when they are preterm) in the earliest days of life, which increases the enterohepatic circulation of bilirubin. Also, if polycythemia is present, the bilirubin load increases.

Respiratory distress syndrome Respiratory Distress Syndrome in Neonates Respiratory distress syndrome is caused by pulmonary surfactant deficiency in the lungs of neonates, most commonly in those born at < 37 weeks gestation. Risk increases with degree of prematurity... read more (RDS) may occur because elevated insulin levels decrease surfactant production; pulmonary maturation may thus be delayed until late in gestation. RDS may develop even if the infant is delivered late preterm or term. Treatment of respiratory distress syndrome Infants of diabetic mothers (IDMs) is discussed elsewhere.

Transient tachypnea of the newborn Infants of diabetic mothers (IDMs) is 2 to 3 times more likely in IDMs because of the delay in fetal lung fluid clearance.

Congenital anomalies are more likely in IDMs because maternal hyperglycemia at the time of organogenesis is detrimental. Specific anomalies include

Persistently elevated insulin levels can also lead to increased deposition of glycogen and fat into cardiomyocytes. This deposition can cause transient hypertrophic cardiomyopathy, predominantly of the septum.