What is the optimal anesthesia plan for a woman in active labor who has Hashimoto's thyroiditis, is clinically euthyroid, and has insulin‑controlled gestational diabetes mellitus?

Anesthesia Management for Pregnant Patient in Labor with Hashimoto's Thyroiditis (Clinically Euthyroid) and Insulin-Controlled GDM

Early epidural analgesia with local anesthetics (with or without opioids) is the optimal anesthesia plan for this patient, as it provides effective labor pain relief while avoiding general anesthesia and its associated airway risks, and can be extended to surgical anesthesia if emergency cesarean section becomes necessary. 1

Primary Anesthetic Approach

Regional Analgesia Strategy

• Initiate epidural analgesia early in labor to reduce maternal stress and anxiety, which is particularly important given the metabolic demands of labor in a patient with GDM 1

• Consider needle-through-needle combined spinal-epidural (CSE) technique as it provides more reliable analgesia than epidural alone, with free flow of cerebrospinal fluid confirming correct midline placement and reducing risk of inadequate block extension for surgery 1

• Avoid systemic opioids as they suppress cough, suppress ventilation, and may induce bowel obstruction, while a cautiously titrated epidural provides superior analgesia 1

Glycemic Management During Labor

Intrapartum Glucose Control

• Target maternal blood glucose between 5-10 mmol/L (0.9-1.8 g/L) during labor, with hourly capillary blood glucose monitoring 1

• Initiate intravenous insulin (IVES) therapy to replace subcutaneous insulin injections during active labor, continuing until return to the postpartum recovery unit 1

• Administer 10% glucose infusion at 40 mL/hour to prevent maternal hypoglycemia and ketosis during the energy-demanding active phase of labor 1

• Administer corrective ultra-rapid insulin analogue bolus if capillary blood glucose exceeds 10 mmol/L (1.8 g/L) 1

Critical Neonatal Risk Consideration

• Alert the neonatal team in advance that the infant will require close glucose monitoring for 24-48 hours postpartum, as maternal hyperglycemia during labor significantly increases neonatal hypoglycemia risk (prevalence 10-40% in GDM) 1, 2

• Maintain strict maternal glycemic control as high capillary blood glucose during labor is directly predictive of neonatal hypoglycemia in multiple logistic regression models 3

Thyroid-Specific Anesthetic Considerations

Airway Assessment and Planning

• Document baseline airway assessment including Mallampati score, neck movement, mouth opening, and thyromental distance, as Hashimoto's thyroiditis can be associated with thyroid enlargement that may complicate airway management 1

• The clinically euthyroid state eliminates thyroid-specific anesthetic concerns as proper levothyroxine therapy during pregnancy normalizes thyroid function and eliminates pregnancy complications associated with hypothyroidism 4

• Prepare backup plan for failed epidural extension including videolaryngoscopy equipment and personnel skilled in emergency airway management, though this risk is minimized with proper epidural technique 1

Mode of Delivery Considerations

Labor vs. Cesarean Decision

• Allow spontaneous labor unless obstetric indications dictate otherwise, as cesarean section should be performed for obstetric indications rather than metabolic disease alone 1

• Recognize increased cesarean risk (1.4-fold higher in GDM compared to non-diabetic patients), necessitating readiness to extend epidural block to surgical anesthesia 1

Factors Associated with Failed Epidural Extension

• Monitor for increased number of analgesic boluses during labor as this predicts failure to adequately extend labor epidural for cesarean section 1

• Ensure specialized obstetric anesthesia coverage as non-specialized anesthesia providers have higher rates of inadequate block extension 1

Common Pitfalls to Avoid

Metabolic Management Errors

• Never allow maternal blood glucose to exceed 16.5 mmol/L (3 g/L) as this level mandates postponement of elective procedures and initiation of corrective therapy 1

• Do not discontinue glucose infusion prematurely in insulin-treated patients, as labor is an energy-consuming state requiring continuous glucose supply to prevent maternal hypoglycemia and ketosis 1

Anesthetic Technique Errors

• Avoid general anesthesia unless absolutely necessary as pregnant patients have increased airway difficulty risk, reduced safe apnea time, and higher aspiration risk 1

• Do not delay epidural placement as early insertion allows time to troubleshoot inadequate blocks and provides the option to extend to surgical anesthesia if urgent cesarean becomes necessary 1

Postpartum Management

Immediate Post-Delivery Period

• Adjust glycemic targets to 6-8.8 mmol/L (1.10-1.60 g/L) after vaginal delivery, which are less strict than intrapartum targets 1

• Resume basal-bolus insulin regimen with decreased doses (typically 30-50% reduction from pregnancy doses) as insulin resistance rapidly decreases postpartum 1

• Continue epidural analgesia postpartum if needed for perineal repair or pain management, as this avoids systemic opioids that may interfere with breastfeeding initiation 1