Respiratory Distress Syndrome (RDS) is the Most Likely Neonatal Complication
In a full-term neonate born to a mother with uncontrolled diabetes, respiratory distress syndrome is the most likely complication to increase, despite the infant being at term. This occurs because maternal hyperglycemia inhibits fetal surfactant production, creating a unique vulnerability even in term infants. 1, 2
Pathophysiologic Mechanism
Maternal hyperglycemia directly impairs fetal lung maturation by inhibiting surfactant production in the developing fetal lung. 2 This mechanism explains why infants of diabetic mothers face increased RDS risk even at term, when lung maturity would typically be expected. The risk is quantified with odds ratios of 2.1 for Type 1 diabetes, 1.7 for Type 2 diabetes, and 1.3 for gestational diabetes compared to non-diabetic pregnancies. 1
The degree of risk correlates directly with glycemic control during pregnancy, as reflected by elevated HbA1c levels. 1 Poor control throughout pregnancy compounds the surfactant deficiency, making RDS more likely and potentially more severe. 3, 4
Why Other Options Are Less Likely
Neonatal Hypoglycemia (Not Hyperglycemia)
The neonate will develop hypoglycemia, not hyperglycemia (Option A is incorrect). 1 Here's the critical sequence:
- Maternal hyperglycemia induces fetal hyperinsulinism in utero 1, 5
- At birth, maternal glucose supply stops immediately 1
- Fetal hyperinsulinism persists for 24-48 hours postpartum 1
- This creates profound neonatal hypoglycemia with prevalence of 10-40% 1
- The risk is highest with Type 1 diabetes, macrosomia, or prematurity 1
- Neurological consequences can be severe and permanent, related to duration and severity of hypoglycemic episodes 1
Polycythemia (Not Low Hemoglobin)
Neonates of diabetic mothers develop polycythemia (elevated hemoglobin), not anemia (Option B is incorrect). 6 The rate of polycythemia is actually significantly lower in cesarean deliveries compared to vaginal deliveries in this population. 6
Transient Tachypnea of the Newborn
While transient tachypnea of the newborn (TTN) can occur, RDS is the more specific and clinically significant respiratory complication in diabetic pregnancies (Option C is less likely than D). 3, 4 RDS occurs despite lung maturity due to insulin's direct effect on surfactant production, making it the characteristic respiratory complication. 3
Clinical Management Priorities
Immediate respiratory assessment and glucose monitoring are mandatory at delivery. 2
Respiratory Management
- Start with supplemental oxygen or CPAP rather than immediate intubation 2
- Prepare for surfactant administration if oxygen requirements exceed 30-40% FiO₂ on CPAP 2
- Escalate systematically based on respiratory status 2
Metabolic Monitoring
- Blood glucose must be monitored immediately and maintained between 90-180 mg/dL during the transition period 2
- This prevents hypoglycemia and subsequent neurological injury 2
- Monitor for secondary complications including hyperbilirubinemia 3, 4, 6
Additional Complications to Anticipate
Beyond RDS and hypoglycemia, these neonates face multiple risks:
- Macrosomia (OR 7.7 for Type 1 diabetes, 3.8 for Type 2 diabetes) 1, 3
- Hyperbilirubinemia and jaundice (significantly higher in cesarean sections following labor) 3, 4, 6
- Hypertrophic cardiomyopathy from fetal hyperinsulinemia 1, 3
- Birth trauma including shoulder dystocia, brachial plexus injuries, and fractures 3
- Increased NICU admission rates (9.8% in GDM vs 0% in controls) 4
- Perinatal mortality (OR 3.6 for Type 1 diabetes, 1.8 for Type 2 diabetes) 1
Critical Pitfall
Do not assume lung maturity based solely on gestational age at term in diabetic pregnancies. 2, 3 The inhibitory effect of maternal hyperglycemia on surfactant production creates a unique vulnerability that persists even at 37+ weeks gestation, distinguishing these infants from the general term population.