For the pregnant woman with either pre-existing diabetes or significant glucose intolerance developing during pregnancy, there are risks to both the mother and the fetus.

Maternal risks

• Preeclampsia

• Hypoglycemia

• Ketoacidosis

• Pyelonephritis

Fetal risks

• Macrosomia

• Polyhydramnios and preterm labor

• Shoulder dystocia and birth trauma

• Respiratory distress syndrome

• Fetal anomalies
  • 5 to 10% incidence
  • May be responsible for up to 50% of fetal deaths in diabetic mothers
  • Neural tube defects and cardiac defects
  • Sacral agenesis is increased 400-fold

• Fetal demise in uncontrolled diabetes
  • Pedersen hypothesis: high maternal glucose load stimulates fetal pancreatic hypertrophy
  • High insulin output in the fetus can result in dangerous hypoglycemia if maternal glucose levels drop