Episode Overview

Podcast: Dr. Chapa’s OBGYN Clinical Pearls
Episode: CGMs in GDM: Evolving Support
Release Date: April 6, 2026
Host: Dr. Chapa

This episode explores the rapidly evolving use of continuous glucose monitors (CGMs) in the management of gestational diabetes mellitus (GDM). Dr. Chapa provides a lively tour through recent evidence, notable clinical trials, and consensus statements—from 2022 to 2026—highlighting both the promise and ongoing uncertainties around CGMs in this context. The episode is clinically focused and delivered in Dr. Chapa's conversational, energetic style, aiming to keep clinicians up to date and engaged with the latest developments in women's health.

Key Discussion Points & Timeline

1. Historical Context & Evolution in Diabetes Care

• [00:37]–[03:00]:
  • Medicine has come a long way from the days of "water tasters" (who literally tasted urine to detect diabetes because of its sweetness).
  • Modern management includes once-weekly insulins and advanced monitoring devices.
  • CGMs and closed-loop systems have revolutionized diabetes care, with type 1 diabetes being the initial primary focus.
  • Notable quote:
    Dr. Chapa [00:37]:
    “It was somebody’s job to taste the water…coming out of your urethra...to see if they could detect that sweet, that kind of honey flavor of the urine, because that would mean the patient had diabetes. That was an actual thing. So thank goodness we've come this far.”

2. Where Are We Now With CGMs in Pregnancy?

• [03:01]–[05:30]:
  • CGMs are well established for Type 1 diabetes in pregnancy, also with growing support in Type 2 diabetes.
  • Gestational Diabetes Mellitus (GDM) is the "newcomer" for potential CGM benefit—recent data has prompted more careful consideration of their use here.
  • Standard GDM management remains four daily finger-stick glucose checks.
  • The evolving focus: Does using CGMs in GDM impact outcomes, and can we interpret the new data appropriately?

3. Key Concepts: Time in Range (TIR) and Monitoring Goals

• [09:00]–[11:30]:
  • Shift from single glucose measurements (fasting/postprandial) to tracking percentage of time spent in target glucose range (TIR).
  • For Type 2 diabetes/GDM: Target TIR generally >90% (some say 85%).
  • For Type 1 diabetes: TIR target generally >70%.
  • Key goal: Keep mean glucose below 110 mg/dL for optimal birth outcomes.
  • Notable quote:
    Dr. Chapa [09:55]:
    “It’s not just fasting under 95 or 2 hours postprandial under 120. We have to understand TIR...greater than 90% desired for these patients with type 2 diabetes or GDM.”

4. Rapid-Fire Review: Major Studies, 2022–2026

a. Meta-Analysis 2022

• [12:00]–[12:50]:
  • 6 RCTs, 482 women with GDM.
  • Findings: CGM use linked to lower A1C, less gestational weight gain, lower infant birth weight.
  • Reference: Diabetes Medicine, Jan 2022.

b. Steady Sugar Trial (Nov 2025)

• [13:00]–[14:00]:
  • 120 women with GDM; compared Dexcom G6 CGM to standard finger-stick monitoring.
  • CGM group had:
    • Lower unscheduled c-section rates
    • Lower preterm deliveries
    • Lower rates of LGA (large for gestational age) and NICU admissions.
  • Reference: Journal: Diabetes, Nov 2025.

c. Valent RCT (2025)

• [17:50]–[18:45]:
  • Randomized trial by Amy Valent, published in Diabetes Care.
  • CGM led to higher TIR, lower daytime mean glucose, and better overall glycemic control than finger-sticks.
  • Quote:
    Dr. Chapa [18:01]:
    “In patients with gestational diabetes who wear real-time continuous glucose monitoring, they were able to achieve significantly higher time in range...compared to capillary blood sugar monitoring alone.”

d. Burk et al Meta-Analysis (Sept 2025)

• [18:46]–[19:15]:
  • 5 RCTs, reinforced findings: CGMs significantly reduced A1C and large for gestational age (LGA) births.

e. Digest Trial Secondary Analysis (Aug 2025)

• [19:16]–[20:00]:
  • Better birth weight outcomes seen in those with TIR >90% and mean glucose <110.

f. GRACE Trial (Jan 2026)

• [20:01]–[20:40]:
  • N=170; open-label RCT.
  • CGM associated with improved infant birth weights with tighter time in range management.

g. SMFM 2026 (Amy Valent Presentation)

• [20:41]–[21:15]:
  • CGM use in GDM led to less NICU admission, fewer respiratory issues, and fewer traumatic birth events.

h. DipGlumo Trial (Feb 2026, Lancet Diabetes Endocrinology)

• [21:16]–[22:40]:
  • Large RCT found no significant difference in hard outcomes (maternal/neonatal complications) vs. standard care.
  • However, patient preference and satisfaction were much higher; participants favored CGM over frequent finger-sticks.
  • Quote:
    Dr. Chapa [22:00]:
    “You think? I mean, did we need an RCT to figure out, hey, patients would rather pick themselves in the arm once for 10 to 14 days vs. four times a day.”

Notable Quotes & Memorable Moments

• [00:37] Dr. Chapa:
  “It was somebody’s job to taste…urine…to see if they could detect that sweet, that kind of honey flavor...So thank goodness we've come this far.”

• [09:55] Dr. Chapa:
  “It’s not just fasting under 95 or 2 hours postprandial under 120. We have to understand TIR...greater than 90% desired for these patients.”

• [18:01] Dr. Chapa (on the Amy Valent 2025 RCT):
  "In patients with gestational diabetes who wear real-time continuous glucose monitoring, they were able to achieve significantly higher time in range...compared to capillary blood sugar monitoring alone..."

• [22:00] Dr. Chapa (on the DipGlumo trial):
  “Did we need an RCT to figure out, hey, patients would rather pick themselves in the arm once for 10 to 14 days versus four times a day? So yeah, it had better patient satisfaction which led to better compliance.”

• [22:50] Dr. Chapa:
  “Even though there was no significant improvement or maternal complication decrease in the CGMs compared to standard care...it’s unfortunate my patients can’t afford it...not yet really universally covered, which is a big gap.”

Take-Home Insights & Evolving Questions

• CGMs for GDM are an exciting, rapidly changing area.

  • Most robust outcome benefit data remain in type 1 and type 2 diabetes, but GDM evidence is catching up.

• Key benefits:

  • Lower A1C, less gestational weight gain, improved birth weights, fewer NICU admissions (in several trials).
  • Clear improvements in patient satisfaction and compliance—"not having to treat them like pin cushions."

• Remaining challenges:

  • Large trial (DipGlumo) found no significant hard outcome difference vs. standard care; not all experts agree on CGMs' impact.
  • Cost and access remain real-world hurdles, especially for publicly funded patients.

• Clinical pearls:

  • "Time in Range" is a crucial metric—aim for >90% in GDM and type 2 diabetes, with mean glucose ideally under 110 mg/dL for best neonatal outcomes.
  • Interpretation and optimal thresholds for GDM-specific CGM use still need refinement.

• Ongoing research:

  • Clinical trials are currently recruiting; field is advancing quickly.
  • Recently published international consensus recognizes CGMs as a tool for GDM but highlights remaining knowledge gaps (especially around optimal glucose ranges).

Conclusion and Final Thoughts

Dr. Chapa wraps up with an acknowledgment of the progress in diabetes management—moving from crude, uncomfortable diagnostics to sophisticated, patient-friendly technology. While standard care for GDM is still based on self-monitored capillary glucose, CGMs are showing real promise for improving outcomes and the patient experience. Ongoing research is set to refine guidance and expand access, with Dr. Chapa enthusiastically supporting their adoption where feasible.

[23:35] Dr. Chapa (paraphrased): “Is there data—even in its infancy—that CGMs can improve some outcomes for GDM? Yes, no question. Gaps remain, but we can’t ignore their value for patient care and satisfaction.”

For clinicians, trainees, and healthcare providers, this episode offers a fast-paced, evidence-packed review of the latest on CGMs in GDM—including the studies you need to know—along with spirited commentary and a call to keep evolving your practice as the data evolve.