Fueling Labor: Protein Supplementation for Intrapartum Glucose Control

Fueling Labor: A Pilot Randomized Controlled Trial of High-Protein Supplementation During Labor to Improve Glucose Control in Insulin-Treated Diabetes Using Continuous Glucose Monitoring

The goal of this study is to learn if high-protein drinks during labor can improve blood sugar control in pregnant women with insulin-treated diabetes. It will also help us learn if this approach is acceptable and well-tolerated by patients. The main questions it aims to answer are:

• Does drinking high-protein beverages during labor keep blood sugar in a healthier range compared to drinking standard clear liquids?
• How do participants feel about drinking protein beverages during labor, and does it affect their energy levels and birth experience?
• Is the baby less likely to have low blood sugar after birth when the mother drinks protein beverages during labor?

Researchers will compare women who drink high-protein beverages to women who drink standard clear liquids (like juice, broth, and popsicles) to see if protein drinks help keep blood sugar more stable during labor.

Participants will:

• Wear a small, painless glucose sensor on their arm from when labor starts until about one week after giving birth
• Be randomly assigned to either drink a clear protein beverage every 4 hours during labor OR drink standard clear liquids as usual
• Complete short surveys about how tired they feel during labor, their overall birth experience, and their overall experience with the glucose sensor

Background and Rationale:

Optimal nutrition during labor for patients with insulin-treated diabetes in pregnancy remains poorly defined. While current guidelines support clear liquid intake during labor, the metabolic effects of different nutritional strategies-particularly high-protein supplementation-have not been studied. Maintaining stable maternal glucose levels during labor is essential to reducing neonatal complications, including hypoglycemia. However, standard clear liquids may cause glucose excursions, while prolonged fasting may contribute to maternal fatigue and metabolic stress.

Continuous glucose monitoring (CGM) technology provides real-time assessment of glucose patterns during labor, offering a novel opportunity to evaluate how targeted nutritional interventions influence maternal glycemic stability. Recent evidence suggests that maternal time above glucose target range during labor is associated with neonatal hypoglycemia, yet no studies have examined whether protein-based oral supplementation can improve intrapartum glucose control compared to standard clear liquids.

Study Objectives:

This pilot randomized controlled trial evaluates the feasibility and metabolic impact of high-protein oral supplementation during labor in patients with insulin-treated gestational or type 2 diabetes undergoing induction of labor. The study aims to:

1. Assess feasibility and acceptability of implementing a CGM-guided intrapartum nutritional protocol
2. Compare CGM-derived glycemic metrics (including percent time above range >110 mg/dL, time in range, and glycemic excursions) between high-protein supplementation and standard clear liquids
3. Explore associations with maternal experience (fatigue, birth satisfaction) and neonatal outcomes

Study Design:

Sixty participants with insulin-treated gestational diabetes (GDM A2) or type 2 diabetes will be randomized 1:1 to receive either high-protein nutritional supplements (30g protein, 0g carbohydrate) every 4 hours during labor or standard institutional clear liquid diet. All participants will wear a blinded CGM (Abbott Freestyle Libre) from admission through delivery and for up to 7 days postpartum. The primary outcome is percent time above glucose range (>110 mg/dL) during labor. Secondary outcomes include other CGM metrics, maternal fatigue and satisfaction scores, labor outcomes, and neonatal hypoglycemia.

Significance:

This pilot study will generate critical preliminary data on the metabolic effects, patient-centered outcomes, and feasibility of high-protein intrapartum supplementation, informing the design of future larger trials to optimize evidence-based nutritional management during labor for patients with insulin-treated diabetes.

Inclusion Criteria:

• Age ≥18 years
• Singleton pregnancy
• Gestational age ≥37 0/7 weeks at time of induction
• Diagnosis of gestational diabetes requiring insulin therapy (GDM A2) or pre-existing Type 2 diabetes managed with insulin during pregnancy
• Admission to labor and delivery for induction of labor
• Able and willing to provide informed consent

Exclusion Criteria:

• Type 1 diabetes mellitus
• Multifetal gestation
• Major fetal anomalies or conditions affecting neonatal glucose regulation
• Stillbirth
• Planned cesarean delivery
• Inability to provide consent
• Contraindication to oral intake (e.g., NPO status for clinical indication)
• Known allergy or intolerance to study materials, including components of the high-protein supplement or CGM device