How is a diabetic pregnant woman managed during the second stage of labor?

Management of Diabetic Pregnant Women During Second Stage of Labor

During the second stage of labor (active pushing and expulsion), diabetic women require continuation of intravenous insulin-glucose infusion with frequent glucose monitoring to maintain maternal glucose between 4.0-7.0 mmol/L (72-126 mg/dL), as insulin requirements that decreased to zero during first stage labor return during active pushing. 1, 2

Insulin Management During Second Stage

Resumption of Insulin Requirements

• Insulin requirements return during the second stage of labor after decreasing to zero during active first stage labor. 2
• Continue the intravenous insulin-glucose infusion protocol that was initiated during first stage labor for women with Type 1 diabetes, Type 2 diabetes, and gestational diabetes requiring insulin. 1, 3
• Adjust insulin infusion rates based on hourly capillary blood glucose measurements and glucose trends, not just absolute values. 4, 5

Specific Insulin Protocols

• For Type 1 and Type 2 diabetes: Maintain intravenous insulin infusion (IVES) throughout second stage, with rates typically ranging 0-5 units/hour based on glucose levels. 1, 5
• For women using insulin pumps: If the pump was retained during first stage (with personalized protocol), consider switching to IV insulin for better control during the more unpredictable second stage. 1
• Never interrupt insulin therapy in Type 1 diabetes patients due to high risk of ketoacidosis, even with moderately elevated glucose levels. 1, 3

Glucose Monitoring and Targets

Target Glucose Range

• Maintain maternal glucose between 4.0-7.0 mmol/L (72-126 mg/dL) during second stage labor to minimize neonatal hypoglycemia risk. 6, 4
• Some protocols successfully use a tighter target of 4.0-6.0 mmol/L (72-108 mg/dL), which results in lower rates of neonatal hypoglycemia. 6

Monitoring Frequency

• Check capillary blood glucose hourly during second stage labor. 4, 5
• Each glucose measurement should prompt evaluation for insulin-glucose infusion rate adjustments. 4, 5

Relationship to Neonatal Outcomes

• Maternal glucose levels during the final 120 minutes before delivery are significantly associated with neonatal hypoglycemia and need for IV glucose treatment in the newborn. 6, 7
• Higher maternal glucose at delivery correlates with lower neonatal glucose levels (inverse relationship). 6, 5

Glucose Infusion Management

Dextrose Administration

• Continue 10% glucose infusion alongside insulin throughout second stage labor. 1, 3
• The glucose infusion prevents maternal hypoglycemia and ketosis during the high energy demands of active pushing. 1
• Glucose requirements remain relatively constant at approximately 2.55 mg/kg/minute during labor. 2

Adjustments Based on Glucose Levels

• If maternal glucose falls below 3.6 mmol/L (65 mg/dL), increase dextrose infusion rate before reducing insulin. 5
• If glucose exceeds 7.0 mmol/L (126 mg/dL), increase insulin infusion rate incrementally. 4, 5

Special Considerations by Diabetes Type

Type 1 Diabetes

• These women have the highest risk of ketoacidosis during labor, even at lower glucose levels than non-pregnant state. 1
• Maintain continuous insulin infusion throughout second stage without interruption. 1, 3
• Monitor for signs of ketosis if glucose control becomes difficult. 1

Type 2 Diabetes

• Often require higher insulin doses than Type 1 patients due to insulin resistance, sometimes necessitating concentrated insulin formulations. 1
• Follow same IV insulin-glucose protocol as Type 1 diabetes during second stage. 1

Gestational Diabetes

• Women requiring ≥0.5 units/kg/day of insulin during pregnancy should use the IV insulin-glucose protocol during second stage. 4
• Women with diet-controlled GDM or requiring <0.5 units/kg/day may only need glucose monitoring without IV insulin during second stage. 6, 4
• Use IV insulin only if glucose exceeds 8.25 mmol/L (140 mg/dL) during labor. 1

Common Pitfalls and How to Avoid Them

Critical Errors to Prevent

• Never discontinue insulin infusion in Type 1 diabetes patients during second stage—this rapidly leads to ketoacidosis. 1, 3
• Avoid relying solely on absolute glucose values; adjust insulin based on glucose trends to prevent overshooting targets. 5
• Don't stop glucose infusion even if maternal glucose is elevated—adjust insulin instead to prevent ketosis. 1

Hypoglycemia Prevention

• Maternal hypoglycemia during second stage can impair maternal effort and fetal oxygenation. 5
• If glucose drops below 3.0 mmol/L (54 mg/dL), immediately increase dextrose infusion and reduce insulin rate. 4, 5
• The overall rate of severe maternal hypoglycemia (≤3.0 mmol/L) should be kept below 2% with proper protocol adherence. 4

Hyperglycemia Management

• Glucose levels >7.0 mmol/L (126 mg/dL) during second stage significantly increase neonatal hypoglycemia risk. 6, 4
• Incrementally increase insulin infusion rather than making large adjustments that may cause subsequent hypoglycemia. 5

Transition to Immediate Postpartum

Preparation for Delivery

• Continue IV insulin-glucose protocol through delivery of the baby. 1
• Have plan ready for dramatic insulin dose reduction immediately after placental delivery. 8, 3

Post-Delivery Changes

• Insulin requirements drop dramatically (to approximately 34% lower than pre-pregnancy levels) immediately after placental delivery. 8
• Prepare to reduce insulin to either 80% of pre-pregnancy doses or 50% of end-pregnancy doses for Type 1 diabetes. 1, 8
• Target glucose range becomes less strict postpartum: 6-8.8 mmol/L (110-160 mg/dL) after vaginal delivery. 1, 8