What is the most important complication to monitor in a full-term baby admitted to the Neonatal Intensive Care Unit (NICU) due to Intrauterine Growth Restriction (IUGR)?

Hypoglycemia is the Most Critical Complication to Monitor

The most important complication to monitor in a full-term IUGR infant admitted to the NICU is hypoglycemia (not listed in your options A-D, but this is the correct answer based on the strongest evidence). If forced to choose from your options, hypothermia (C) would be second priority, but hypoglycemia remains the primary concern.

Why Hypoglycemia Takes Priority

Pathophysiologic Vulnerability

• IUGR infants have severely depleted glycogen and fat stores due to chronic placental insufficiency, making them uniquely vulnerable to hypoglycemia 1
• Nearly 30-60% of IUGR infants develop hypoglycemia requiring immediate intervention 2
• The degree of placental insufficiency (reflected in abnormal Doppler studies) directly correlates with hypoglycemia severity 1

Immediate Risk and Consequences

• Hypoglycemia occurs acutely in the first hours after birth when the placental glucose supply is suddenly interrupted 2
• IUGR infants cannot mount adequate counter-regulatory responses and lack functional gluconeogenesis pathways 2
• Infants with reversed end-diastolic flow on prenatal umbilical artery Doppler face the highest risk for severe early hypoglycemia and require the most intensive monitoring 1

Monitoring Algorithm for IUGR Infants

First Priority: Hypoglycemia Surveillance

• Begin glucose monitoring within 30 minutes of birth and continue every 1-3 hours until stable feeds established 2, 3
• Target glucose levels >45-50 mg/dL in the first 24 hours 2
• Risk stratify based on prenatal Doppler findings—reversed end-diastolic flow indicates highest metabolic compromise 1

Second Priority: Hypothermia Prevention

• IUGR infants have reduced subcutaneous fat and increased surface area-to-body mass ratio, predisposing to heat loss 3, 4
• Hypothermia exacerbates hypoglycemia by increasing metabolic demands 3
• Maintain neutral thermal environment immediately after delivery 4

Additional Acute Complications to Monitor

• Perinatal asphyxia: IUGR infants tolerate labor poorly and have higher rates of acidosis 4, 5
• Polycythemia: Chronic hypoxemia drives increased red blood cell production 3, 4
• Coagulation abnormalities: Thrombocytopenia and coagulopathy occur more frequently 4

Common Pitfalls to Avoid

• Don't rely on normal prenatal heart rate testing: Normal fetal heart rate patterns do not exclude severe metabolic compromise in IUGR infants 6
• Don't delay glucose screening: Waiting for clinical symptoms means hypoglycemia has already caused potential neurologic injury 2
• Don't underestimate prematurity complications: Even full-term IUGR infants have increased risk for respiratory distress, necrotizing enterocolitis, and chronic lung disease compared to appropriately grown infants 4

Regarding Your Answer Choices

• Hyperglycemia (A): Not a primary concern in IUGR infants; hypoglycemia is the metabolic emergency 2, 3
• Hypocalcemia (B): Can occur but is not the most critical immediate complication 3
• Hypothermia (C): Important and common, but secondary to hypoglycemia in priority 3, 4
• Anemia (D): IUGR infants typically develop polycythemia (elevated hematocrit), not anemia 3, 4