Gestational Diabetes · Newport Beach · 2026

Gestational Diabetes Management
Diagnosis, Diet & Treatment

Understanding your diagnosis. Controlling your numbers. Protecting your pregnancy.

Gestational diabetes is one of the most common medical complications of pregnancy, but with proper management, the vast majority of women have healthy outcomes. This guide covers the ACOG-recommended screening process, blood glucose targets, dietary strategies, when medication is needed, fetal monitoring, and what happens after delivery.

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◆ Short Answer

The Canonical Answer

Gestational diabetes mellitus (GDM) affects 6 to 9 percent of pregnancies in the United States and is caused by placental hormones that create progressive insulin resistance ACOG PB #190. Screening is universal at 24 to 28 weeks using a two-step approach: a 1-hour 50-gram glucose challenge test, followed by a 3-hour 100-gram glucose tolerance test if the initial screen is abnormal ACOG PB #190. First-line treatment is dietary modification — carbohydrate distribution across meals and snacks, with referral to a diabetes educator. If glucose targets (fasting ≤95, 1-hour postprandial ≤140, 2-hour postprandial ≤120) are not met within 1–2 weeks, insulin is the preferred pharmacologic agent ACOG PB #190; ADA Standards 2024. Fetal surveillance includes serial growth ultrasounds and antenatal testing. GDM typically resolves after delivery, but carries a 50 percent lifetime risk of developing type 2 diabetes, requiring postpartum and annual screening ADA Standards 2024. At Broad Medical Group, Dr. Jennifer Broad manages gestational diabetes from diagnosis through postpartum follow-up for patients in Newport Beach and Orange County.

Medically reviewed by Dr. Jennifer Broad, MD, FACOG Board-Certified Obstetrician-Gynecologist · Newport Beach, CA

Last reviewed: April 2026 Next review: October 2026

Pregnant woman reviewing blood glucose log with her OBGYN at Broad Medical Group in Newport Beach

What Is Gestational Diabetes?

Gestational diabetes mellitus (GDM) is defined as glucose intolerance that is first recognized during pregnancy. It is one of the most common medical complications of pregnancy, affecting approximately 6 to 9 percent of pregnancies in the United States, though prevalence has been rising in parallel with obesity rates.

During pregnancy, the placenta produces hormones — including human placental lactogen, cortisol, and progesterone — that progressively increase insulin resistance. This is a normal physiological adaptation designed to ensure adequate glucose delivery to the growing fetus. In most women, the pancreas compensates by producing more insulin. In women who develop gestational diabetes, the pancreas cannot keep pace with the increasing demand, and blood glucose levels rise above the normal range.

Gestational diabetes is not a failure of willpower or diet. It is a metabolic condition driven by the hormonal environment of pregnancy. Understanding this distinction is important: it reduces unnecessary guilt and focuses attention on what matters — effective management to protect both mother and baby.

Risk Factors for Gestational Diabetes

While any pregnant woman can develop GDM, certain factors increase risk. The presence of risk factors may warrant early screening before 24 weeks:

BMI ≥30 (obesity at the start of pregnancy)
Prior gestational diabetes in a previous pregnancy
Polycystic ovary syndrome (PCOS)
Family history of type 2 diabetes (first-degree relative)
Hemoglobin A1c ≥5.7% in early pregnancy
Prior macrosomic infant (birth weight >4,000g / 8 lb 13 oz)
Advanced maternal age (≥35 years)
Certain ethnic backgrounds with higher prevalence (Hispanic, African American, South Asian, Pacific Islander, Indigenous)

Gestational diabetes is a condition managed within the broader context of high-risk pregnancy care. At Broad Medical Group, Dr. Broad integrates GDM management into your overall prenatal plan, coordinating with diabetes educators, nutritionists, and maternal-fetal medicine specialists when needed. For the full scope of routine pregnancy monitoring, see our prenatal care guide.

Diagnosis: The Two-Step Screening

ACOG PB #190 ADA 2024

The American College of Obstetricians and Gynecologists (ACOG) recommends universal screening for gestational diabetes between 24 and 28 weeks of gestation using a two-step approach. Women with significant risk factors may be screened in the first trimester or early second trimester, and if that early screen is normal, they are rescreened at 24–28 weeks.

ACOG Guideline

Step 1 — Glucose Challenge Test (GCT): You drink a 50-gram glucose solution (no fasting required). Blood glucose is measured at 1 hour. A result of ≥130–140 mg/dL is considered a positive screen and prompts step two. The lower threshold (130) captures more cases; the higher threshold (140) is more specific. Most practices use 135 or 140 as the cutoff.

ACOG Guideline

Step 2 — Glucose Tolerance Test (GTT): After an overnight fast (8–14 hours), you drink a 100-gram glucose solution. Blood glucose is measured at fasting, 1 hour, 2 hours, and 3 hours. Using the Carpenter-Coustan criteria, gestational diabetes is diagnosed when two or more of the following values are met or exceeded:

Measurement	Carpenter-Coustan Threshold
Fasting	≥95 mg/dL
1-hour	≥180 mg/dL
2-hour	≥155 mg/dL
3-hour	≥140 mg/dL

If only one value is abnormal on the 3-hour GTT, the patient does not meet criteria for GDM but is still at increased risk. Many providers will recommend dietary counseling and repeat testing or enhanced glucose monitoring in this scenario.

It is worth noting that a positive 1-hour screen does not mean you have gestational diabetes. Approximately 15–25 percent of women will screen positive on step one, but only a fraction of those will meet diagnostic criteria on step two. The 1-hour test is a screening tool; the 3-hour test is the diagnostic test.

Blood Glucose Targets

Once gestational diabetes is diagnosed, the cornerstone of management is self-monitoring of blood glucose (SMBG). You will check your blood sugar four times daily using a home glucose meter: once in the morning before eating (fasting) and once after each of your three main meals (postprandial). The timing of the postprandial check is typically 1 hour or 2 hours after the start of the meal, depending on your provider’s preference.

Measurement	ACOG Target	When to Check
Fasting	≤95 mg/dL	First thing in the morning, before eating
1-hour postprandial	≤140 mg/dL	1 hour after the start of the meal
2-hour postprandial	≤120 mg/dL	2 hours after the start of the meal

Blood glucose monitoring schedule and ACOG targets visual - fasting, 1-hour and 2-hour postprandial targets displayed on a daily timeline — ACOG-recommended blood glucose targets and daily monitoring schedule for gestational diabetes.

Recording your glucose values in a log — either paper or a smartphone app — is essential. This log is reviewed at every prenatal visit and is the primary tool Dr. Broad uses to assess whether dietary management is working or medication is needed. Patterns matter more than individual readings: a single elevated value after a holiday meal is different from consistently elevated fasting numbers every morning.

Some women find that their fasting values are the hardest to control, even with perfect dietary adherence. This is because fasting glucose is driven largely by the liver’s overnight glucose production, which is under hormonal rather than dietary control. This is a common reason for adding nighttime insulin even when daytime values are well-managed with diet.

Dietary Management

Dietary modification is the first-line treatment for gestational diabetes and is effective as sole therapy in approximately 70–85 percent of women with GDM. The goal is not caloric restriction — pregnancy is not the time to diet — but rather strategic carbohydrate management that prevents the post-meal glucose spikes that pose risk to the fetus.

Patient Tip

You are not “eating for two” in quantity — you are eating strategically for two. The total caloric needs of pregnancy increase by only about 300–450 calories per day in the second and third trimesters. The key with GDM is how you distribute those calories, not how much you restrict them. Severe caloric restriction can cause ketosis, which is harmful to fetal development.

Core Dietary Principles

1. Distribute carbohydrates across the day. Rather than three large meals, structure your intake as three moderate meals and two to three snacks. This prevents large carbohydrate loads at any single sitting, which cause the glucose spikes that GDM management aims to avoid. A common distribution is approximately 30–45 grams of carbohydrates per meal and 15–20 grams per snack, adjusted based on your individual glucose response.

2. Choose complex carbohydrates over simple sugars. Whole grains, legumes, vegetables, and moderate portions of fruit are metabolized more slowly than white bread, juice, candy, or sweetened beverages. The glycemic index matters: steel-cut oats versus instant oatmeal, brown rice versus white rice, whole fruit versus fruit juice.

3. Pair carbohydrates with protein and healthy fat. Eating protein and fat alongside carbohydrates slows gastric emptying and moderates the post-meal glucose rise. Examples: apple with peanut butter rather than apple alone; whole-grain toast with eggs rather than toast with jam; yogurt with nuts rather than yogurt alone.

4. Pay attention to breakfast. Morning insulin resistance is typically at its peak due to the cortisol awakening response. Many women with GDM find that breakfast is the most challenging meal. A lower-carbohydrate, higher-protein breakfast (eggs, cheese, whole-grain toast) is often more effective than cereal, oatmeal, or fruit-heavy options.

5. Include a bedtime snack. A small protein-containing snack before bed (cheese and crackers, a handful of nuts, yogurt) can help stabilize overnight glucose levels and may reduce elevated fasting readings.

Referral to a Diabetes Educator or Dietitian

Dr. Broad refers all patients diagnosed with gestational diabetes to a certified diabetes educator (CDE) or registered dietitian who specializes in pregnancy nutrition. This is not optional — it is a standard component of GDM care. The dietitian will create an individualized meal plan based on your food preferences, cultural traditions, schedule, and glucose response patterns. Most patients see the dietitian within one week of diagnosis and follow up as needed.

When Medication Is Needed

If blood glucose targets are consistently not met after 1 to 2 weeks of dietary management and lifestyle modification, pharmacologic therapy is initiated. This is not a failure — it means the degree of insulin resistance has exceeded what dietary modification alone can manage, which is a function of placental hormone production, not patient effort.

Important

Do not delay starting medication if your provider recommends it. Persistent hyperglycemia increases the risk of fetal macrosomia (excessive birth weight), birth injury, neonatal hypoglycemia, and other complications. The goal of medication is to reach glucose targets quickly. Delaying pharmacologic therapy in hopes of “trying harder with diet” when targets are consistently missed can put both you and your baby at unnecessary risk.

Insulin: The Preferred Agent

Insulin is the first-line pharmacologic agent for gestational diabetes per both ACOG and the American Diabetes Association. The primary advantage of insulin is that it does not cross the placenta, meaning it does not directly affect the fetus. Insulin therapy is tailored to the pattern of glucose elevation:

Elevated fasting glucose: Intermediate-acting insulin (NPH) at bedtime to control overnight hepatic glucose production.
Elevated postprandial glucose: Rapid-acting insulin (lispro or aspart) before meals to manage the post-meal glucose spike.
Both fasting and postprandial elevation: A combination regimen, often called a “split-mix” regimen with both basal and prandial insulin components.

Insulin doses are started conservatively and titrated upward based on glucose log review. As pregnancy progresses, insulin resistance increases — particularly between 28 and 36 weeks — so dose increases are expected and do not indicate worsening disease.

Oral Agents: Metformin and Glyburide

While insulin remains the gold standard, oral medications are sometimes used in clinical practice, particularly when patients have strong concerns about injectable therapy or barriers to insulin use.

Metformin is a reasonable alternative in some cases. It works by reducing hepatic glucose production and improving insulin sensitivity. However, metformin crosses the placenta, and long-term outcome data for children exposed in utero are still being studied. Approximately 30–50 percent of women started on metformin will eventually require supplemental insulin to achieve glucose targets.

Glyburide (a sulfonylurea) was previously used more frequently but has fallen out of favor. Studies have shown a higher failure rate compared to insulin, a higher rate of neonatal hypoglycemia, and a higher rate of macrosomia. ACOG notes that glyburide should not be recommended as a first-line alternative to insulin.

Dr. Broad discusses the evidence for all three options with each patient, including benefits, limitations, and what the data show, so that the treatment decision is informed and individualized.

Fetal Monitoring with GDM

Gestational diabetes increases the risk of certain fetal complications, most notably macrosomia (excessive fetal growth) and its downstream consequences: shoulder dystocia, birth injury, and operative delivery. Careful fetal surveillance is a critical component of GDM management.

Serial Growth Ultrasounds

Fetal growth is assessed with ultrasound to track the estimated fetal weight and identify early signs of macrosomia. Growth scans are typically performed every 3–4 weeks in the third trimester for women with GDM on medication, and at least once in the third trimester for diet-controlled GDM. The abdominal circumference is the most sensitive single measurement for predicting fetal overgrowth related to maternal hyperglycemia.

Antenatal Testing

Nonstress testing (NST) evaluates fetal heart rate reactivity and is used to confirm fetal well-being in the third trimester. The timing and frequency depend on the severity of GDM:

Diet-controlled GDM (A1GDM): Antenatal testing is not universally required but may be initiated at 36–40 weeks or if other risk factors are present.
Medication-controlled GDM (A2GDM): Weekly or twice-weekly antenatal testing is typically initiated at 32 weeks. The standard approach includes NST or biophysical profile (BPP).

Delivery Timing

Gestational diabetes influences the recommended timing of delivery. ACOG provides the following guidance:

Diet-controlled GDM (A1GDM): Delivery at 39 weeks 0 days to 40 weeks 6 days. Expectant management beyond 40 weeks 6 days is not recommended.
Medication-controlled GDM (A2GDM): Delivery at 39 weeks 0 days to 39 weeks 6 days. The rationale is the increased risk of stillbirth and macrosomia-related complications with continued exposure to maternal hyperglycemia.

If the estimated fetal weight exceeds 4,500 grams (approximately 10 pounds) in a woman with GDM, cesarean delivery is typically recommended to reduce the risk of shoulder dystocia. These decisions are made individually, taking into account the full clinical picture.

Postpartum: What Happens After Delivery

In the vast majority of cases, blood glucose levels return to normal within hours to days after delivery. Once the placenta is delivered, the hormonal source of insulin resistance is removed, and glucose metabolism typically normalizes rapidly. Insulin or oral medications are usually discontinued immediately after delivery, with close monitoring in the postpartum period to confirm resolution.

However, gestational diabetes is a powerful predictor of future metabolic disease. The metabolic stress test that pregnancy represents has revealed an underlying vulnerability in glucose regulation that, while compensated outside of pregnancy, may manifest again over time.

The Long-Term Risk: Type 2 Diabetes

Women who have had gestational diabetes have an approximately 50 percent lifetime risk of developing type 2 diabetes. The risk is highest in the first 5–10 years after delivery and remains elevated indefinitely. This is why postpartum follow-up and ongoing screening are essential — not optional.

Postpartum Screening Protocol

ACOG and the ADA recommend a 75-gram, 2-hour glucose tolerance test at 4 to 12 weeks postpartum to determine whether glucose metabolism has fully normalized, or whether the patient has persistent impaired glucose tolerance, prediabetes, or overt type 2 diabetes. This is a different test from the 3-hour GTT used during pregnancy — it uses a 75-gram glucose load and 2-hour measurement, following the standard diagnostic criteria for diabetes in the non-pregnant population.

After the initial postpartum screen, annual screening is recommended for life. This can be done with a fasting glucose, hemoglobin A1c, or 75-gram GTT, depending on clinician preference and patient factors.

Reducing Long-Term Risk

The following strategies have evidence supporting reduction in the progression from GDM to type 2 diabetes:

Breastfeeding: Multiple studies show that breastfeeding is associated with improved postpartum glucose metabolism and may reduce the risk of type 2 diabetes. The mechanism likely involves improved insulin sensitivity and lower postpartum weight retention.
Weight management: Returning to pre-pregnancy weight within the first year postpartum significantly reduces metabolic risk. Even modest weight loss (5–7% of body weight) has been shown to reduce diabetes progression by 58% in the landmark Diabetes Prevention Program trial.
Physical activity: Regular moderate exercise (150 minutes per week) improves insulin sensitivity independent of weight loss.
Dietary habits: Continuing the dietary principles learned during GDM management — distributed meals, complex carbohydrates, protein pairing — supports long-term glucose control.

When to Call Immediately

Contact Dr. Broad’s office or go to Hoag Hospital labor and delivery if you experience any of the following:

Fasting blood glucose consistently above 120 mg/dL despite medication, or any single reading above 200 mg/dL
Symptoms of severe hyperglycemia: excessive thirst, frequent urination far beyond normal pregnancy frequency, blurred vision, persistent headache, or confusion
Signs suggestive of diabetic ketoacidosis (DKA): nausea and vomiting that does not resolve, abdominal pain, fruity-smelling breath, rapid breathing, or feeling extremely unwell — DKA in pregnancy is a medical emergency even at relatively modest glucose levels
Symptoms of hypoglycemia (if on insulin): shaking, sweating, rapid heartbeat, dizziness, confusion, or fainting — treat immediately with 15 grams of fast-acting carbohydrate and call the office
Decreased fetal movement (fewer than 10 kicks in 2 hours during a kick count)

If you are experiencing a medical emergency, call 911.

Key Takeaways

Gestational diabetes affects 6–9% of US pregnancies and is caused by placental hormones creating insulin resistance — it is not caused by dietary choices.
Screening is universal at 24–28 weeks using ACOG’s two-step approach: 1-hour GCT followed by 3-hour GTT if the screen is positive.
Dietary management is the first-line treatment — distributed meals and snacks, complex carbohydrates, protein pairing. Not caloric restriction.
If diet alone is insufficient, insulin is the preferred medication — it does not cross the placenta and is safe for the fetus.
Self-monitoring 4 times daily (fasting + after each meal) is essential. Target: fasting ≤95, 1-hr ≤140, 2-hr ≤120.
GDM usually resolves after delivery, but carries a 50% lifetime risk of type 2 diabetes. Postpartum GTT at 4–12 weeks and annual screening are recommended.

References & Clinical Sources

American College of Obstetricians and Gynecologists. Practice Bulletin No. 190: Gestational Diabetes Mellitus. Obstetrics & Gynecology, 131(2), e49–e64. 2018. Reaffirmed 2024.
American Diabetes Association. Standards of Care in Diabetes — 2024. Section 15: Management of Diabetes in Pregnancy. Diabetes Care, 47(Suppl 1), S282–S294. 2024.
Carpenter MW, Coustan DR. Criteria for screening tests for gestational diabetes. American Journal of Obstetrics and Gynecology, 144(7), 768–773. 1982.
ACOG Committee Opinion No. 764: Medically Indicated Late-Preterm and Early-Term Deliveries. Obstetrics & Gynecology, 133(2), e151–e155. 2019.
Knowler WC, Barrett-Connor E, Fowler SE, et al. Reduction in the Incidence of Type 2 Diabetes with Lifestyle Intervention or Metformin (Diabetes Prevention Program). New England Journal of Medicine, 346(6), 393–403. 2002.
Vounzoulaki E, Khunti K, Abner SC, Tan BK, Davies MJ, Gillies CL. Progression to type 2 diabetes in women with a known history of gestational diabetes: systematic review and meta-analysis. BMJ, 369, m1361. 2020.

Related Resources

Gestational Diabetes. Managed With Confidence.

Diagnosed with GDM or have risk factors? Dr. Broad provides comprehensive gestational diabetes management — from initial screening through postpartum follow-up — for patients in Newport Beach and Orange County.

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Broad Medical Group — Newport Beach, California

Medical Disclaimer: This content is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Consult Dr. Jennifer Broad or your healthcare provider for guidance specific to your situation. Current as of April 2026. If you are experiencing a medical emergency, call 911 immediately.