What are the risks to the infant if gestational diabetes (GD) is left untreated?

Risks to the Infant if Gestational Diabetes is Left Untreated

Untreated gestational diabetes significantly increases the risk of serious perinatal complications for the infant, with a 2-4 fold higher morbidity rate compared to treated cases, including increased risks of perinatal mortality, macrosomia, and metabolic complications. 1

Major Risks to the Infant

Mortality Risks

• Perinatal mortality: Significantly increased risk in untreated gestational diabetes compared to treated cases 2, 1
  • ACHOIS trial showed 5 perinatal deaths in the untreated group versus zero deaths in the treated group 2

Structural/Physical Complications

• Macrosomia (birth weight ≥4,000g):

  • 7.7-fold increased risk compared to non-diabetic pregnancies 2
  • Occurs in up to 35.3% of untreated GDM pregnancies 3
  • Associated with difficult delivery and birth trauma

• Birth trauma:

  • Shoulder dystocia: 42% reduction with treatment 2
  • Brachial plexus injuries
  • Clavicular fractures

Metabolic Complications

• Neonatal hypoglycemia:

  • Prevalence of 10-40% in infants of GDM mothers 2, 4
  • Higher risk with poor maternal glycemic control during pregnancy and labor 2
  • Caused by fetal hyperinsulinism in response to maternal hyperglycemia 2
  • Can lead to neurological complications if severe or prolonged 2
  • Requires monitoring in the first hour of life and every 2-3 hours during first 24 hours 4

• Other metabolic disturbances:

  • Hyperbilirubinemia
  • Hypocalcemia
  • Hypomagnesemia
  • Polycythemia and hyperviscosity 5

Respiratory Complications

• Respiratory distress syndrome:
  • 2.1-fold increased risk compared to non-diabetic pregnancies 2
  • Occurs in up to 31.4% of infants born to mothers with GDM 3
  • Increased need for NICU admission (9.8% vs 0% in non-GDM pregnancies) 3

Long-term Complications

• Childhood obesity
• Type 2 diabetes in adolescence and adulthood
• Metabolic syndrome and cardiovascular disease 4

Risk Stratification

The severity of complications correlates with:

1. Degree of maternal hyperglycemia:

   • Linear relationship between maternal glucose levels and increased birth weight 6
   • Fasting hyperglycemia >105 mg/dl particularly associated with intrauterine fetal death 4

2. Timing of diagnosis and treatment:

   • Early diagnosis and treatment significantly reduces complications 1
   • Composite adverse outcome rates: 59% for untreated vs 18% for treated GDM 1

3. Maternal factors:

   • Obesity compounds risks independent of diabetes status 6
   • Pre-existing diabetes carries higher risks than gestational diabetes 2

Clinical Implications

• Untreated GDM carries significant risks at all severity levels 1
• Treatment reduces the composite adverse outcome rate from 59% to 18% 1
• Macrosomia appears to be the predominant adverse outcome that leads to other complications 6
• The risk of congenital anomalies is slightly increased in GDM, likely due to undiagnosed pre-existing type 2 diabetes 6

Common Pitfalls in Management

1. Delayed diagnosis: Screening should be performed between 24-28 weeks of gestation for optimal outcomes 2

2. Inadequate glucose monitoring: Regular monitoring is essential for detecting and managing hyperglycemia 2

3. Underestimating risks in "mild" GDM: Even mild cases carry significant risks if untreated 1

4. Focusing only on short-term outcomes: Long-term metabolic risks to the child should be considered 4, 7

5. Overlooking neonatal monitoring: Newborns require close monitoring for hypoglycemia and other complications in the first 24-48 hours 2, 4

The evidence clearly demonstrates that untreated gestational diabetes significantly increases risks to the infant, and that timely diagnosis and effective treatment substantially improve outcomes.