OpenMFM Library
PATIENT EDUCATION · UPDATED OCT 2026

A patient & family guide

Gestational diabetes.
A clear plan for the road ahead.

Understand your numbers. Care for your pregnancy. Protect your health after birth.

  1. 01

    Understand

    What the diagnosis means

  2. 02

    Act

    Food, movement & treatment

  3. 03

    Follow through

    Birth & lifelong health

Dr. Chukwuma Onyeije · Atlanta Perinatal Associates

[1] ADA pregnancy care · 2026 [3] ACOG GDM guidance
OpenMFM · Atlanta Perinatal Associates 01 / 32

01 / Understand

Know your numbers.
Know your next step.

By the end, you will be able to:

Explain your test

Know how GDM is diagnosed.

Use your daily plan

Check glucose and know when to ask for help.

Plan beyond birth

Arrange pregnancy follow-up and postpartum testing.

Read in order or use the slide menu to jump to a topic.

[1] ADA pregnancy care · 2026
OpenMFM · Atlanta Perinatal Associates 02 / 32

01 / Understand

Pregnancy makes insulin
work less effectively.

Glucose is sugar in your blood. Insulin helps your body use it for energy.

  1. 01

    Placenta

    Pregnancy hormones increase insulin resistance.

  2. 02

    Pancreas

    Your body needs to make more insulin.

  3. 03

    GDM

    If it cannot keep up, blood glucose rises.

GDM is a health condition, not a personal failure.

[1] ADA pregnancy care · 2026 [2] ADA diagnosis · 2026
OpenMFM · Atlanta Perinatal Associates 03 / 32

01 / Understand

Risk factors matter.
Screening still matters.

GDM can occur even without obvious risk factors.

Your history

Prior GDM, a previous large baby, or a close relative with diabetes.

Your health

PCOS, higher body weight, increasing age, or high blood pressure.

Routine testing helps find GDM that has no symptoms.

Clinician context
Risk varies across populations and reflects biological, social, and health-care factors. Risk factors guide early assessment for unrecognized diabetes; they do not replace routine GDM screening. PCOS means polycystic ovary syndrome.
[2] ADA diagnosis · 2026 [7] USPSTF screening
OpenMFM · Atlanta Perinatal Associates 04 / 32

01 / Understand

Treatment lowers important
pregnancy risks.

The goal is a healthier pregnancy, not a perfect glucose log.

For you

Reduce the risk of pregnancy-related high blood pressure and some delivery complications.

For your baby

Reduce excessive growth and shoulder dystocia: difficulty delivering the shoulders.

After birth, babies may need extra support for low blood glucose.

What the evidence shows
Randomized trials support a package of nutrition counseling, glucose monitoring, follow-up, and insulin when needed. ACHOIS reduced serious perinatal complications. In the MFMU mild-GDM trial, the primary composite did not significantly improve, but excessive growth, shoulder dystocia, cesarean delivery, and hypertensive disorders were reduced. These trials do not prove one medication is best for every outcome.
[5] ACHOIS randomized trial [6] Mild GDM randomized trial [1] ADA pregnancy care · 2026
OpenMFM · Atlanta Perinatal Associates 05 / 32

02 / Testing

Most GDM testing happens
at 24–28 weeks.

Earlier testing answers a different question: was diabetes already present?

  1. 01

    Early pregnancy

    Assess for previously unrecognized diabetes when indicated.

  2. 02

    24–28 weeks

    Use the practice’s standard GDM testing pathway.

A normal early test does not replace later GDM testing.

Clinician context
Overt diabetes may be identified by fasting plasma glucose ≥126 mg/dL or A1C ≥6.5%, with confirmation when appropriate. Mild early hyperglycemia below overt-diabetes criteria has a less settled treatment pathway. Do not automatically apply later-pregnancy GDM thresholds early.
[2] ADA diagnosis · 2026 [4] ACOG screening update · 2024
OpenMFM · Atlanta Perinatal Associates 06 / 32

02 / Testing

An abnormal screen usually
means another test.

The common U.S. two-step pathway starts with a screening drink.

  1. 01

    50-g screen

    No fasting. Blood drawn after 1 hour.

  2. 02

    If screen is elevated

    The practice uses a cutoff of 130, 135, or 140 mg/dL.

  3. 03

    100-g diagnostic test

    Fast beforehand. Blood drawn fasting and at 1, 2, and 3 hours.

The first test screens for risk; the next test usually establishes the diagnosis.

[2] ADA diagnosis · 2026 [3] ACOG GDM guidance
OpenMFM · Atlanta Perinatal Associates 07 / 32

02 / Testing

Some practices use
one diagnostic test.

The one-step pathway uses a fasting 75-g glucose drink.

  1. 01

    Before the drink

    Measure fasting glucose.

  2. 02

    After the drink

    Measure at 1 hour and 2 hours.

  3. 03

    Interpret the results

    One value at or above its threshold establishes GDM.

Follow the preparation instructions for the test your practice orders.

[2] ADA diagnosis · 2026
OpenMFM · Atlanta Perinatal Associates 08 / 32

02 / Testing

The diagnosis rule
depends on the test.

These laboratory cutoffs diagnose GDM. They are not your home glucose goals.

100-g test · two-step

Usually 2 or more abnormal values.

75-g test · one-step

1 or more abnormal values.

Ask which pathway was used before interpreting a result.

View diagnostic thresholds
Diagnostic thresholds, mg/dL; values at or above the cutoff are abnormal
Time 100-g / Carpenter–Coustan 75-g / one-step
Fasting 95 92
1 hour 180 180
2 hours 155 153
3 hours 140 Not measured

Document the local protocol. A single abnormal 100-g value may prompt additional assessment or management under local guidance; do not mix the one-step and two-step rules.

[2] ADA diagnosis · 2026 [3] ACOG GDM guidance
OpenMFM · Atlanta Perinatal Associates 09 / 32

02 / Testing

A1C does not replace
the glucose tolerance test.

A1C reflects average glucose over time. Pregnancy can affect its interpretation.

Useful context

It can help identify previously unrecognized diabetes early.

Daily decisions

Fasting and postmeal readings guide the GDM treatment plan.

A reassuring A1C does not rule out GDM.

[1] ADA pregnancy care · 2026 [2] ADA diagnosis · 2026 [4] ACOG screening update · 2024
OpenMFM · Atlanta Perinatal Associates 10 / 32

03 / Daily care

Start with three
practical tools.

Your team will help you build a plan that fits your life.

Food

Individual nutrition counseling.

Movement

Activity that is safe for your pregnancy.

Monitoring

A meter or agreed device, supplies, and a review plan.

Ask who reviews your readings and how to contact them.

What A1GDM and A2GDM mean
A1GDM describes glucose controlled without medication. A2GDM describes GDM requiring medication. Both need glucose monitoring and obstetric follow-up. These labels describe treatment needs, not personal success.
[1] ADA pregnancy care · 2026 [3] ACOG GDM guidance
OpenMFM · Atlanta Perinatal Associates 11 / 32

03 / Daily care

Check fasting glucose
and one postmeal time.

A common starting routine is four checks each day.

  1. 01

    Morning

    Before breakfast, after the overnight fast.

  2. 02

    After each meal

    At 1 hour OR 2 hours, as your team directs.

  3. 03

    Share the pattern

    Record readings, timing, and relevant food or medication changes.

Agree on when the postmeal clock starts, usually the first bite.

[1] ADA pregnancy care · 2026
OpenMFM · Atlanta Perinatal Associates 12 / 32

03 / Daily care

Three numbers guide
your daily plan.

Common treatment targets, in mg/dL:

Fasting <95 Before breakfast
1 hour after a meal <140 Use this timing
OR
2 hours after a meal <120 Use this timing

Use the goals your team sets, especially if you have low glucose.

[1] ADA pregnancy care · 2026
OpenMFM · Atlanta Perinatal Associates 13 / 32

03 / Daily care

A sensor adds trends.
You still need a plan.

A continuous glucose monitor (CGM) measures glucose in fluid under the skin.

What it adds

Shows patterns between meals and overnight.

What to check

Use a fingerstick when symptoms disagree with the sensor or your device instructions require it.

Ask which readings should guide treatment and when to confirm them.

Clinician context
Tissue and blood glucose can differ, especially during rapid changes. CGM evidence is strongest for type 1 diabetes in pregnancy; GDM use should be individualized. A sensor does not replace the diagnostic glucose tolerance test.
[1] ADA pregnancy care · 2026
OpenMFM · Atlanta Perinatal Associates 14 / 32

03 / Daily care

Keep carbohydrates.
Build a balanced plate.

The goal is enough nutrition with portions that fit your glucose pattern.

Make room for variety

Vegetables, beans, whole grains, protein, and healthy fats can all fit.

Fruit and dairy can fit too; ask about portions.

Avoid skipping meals or cutting carbohydrates too sharply.

Make it personal
The plate is an illustration, not a fixed meal prescription. A dietitian can tailor carbohydrate distribution, snacks, cultural food preferences, gestational weight gain, and food access. Avoid nutritionally inadequate restriction and ketosis.
[1] ADA pregnancy care · 2026
OpenMFM · Atlanta Perinatal Associates 15 / 32

03 / Daily care

Small changes can make
eating easier.

Build a sustainable plan with familiar foods.

Drinks

Choose water or an unsweetened drink more often.

Meals

Try a fiber-rich carbohydrate with protein and vegetables.

Timing

Distribute food across the day; tailor snacks to your needs.

Use your readings to learn what works. No single food defines your care.

[1] ADA pregnancy care · 2026
OpenMFM · Atlanta Perinatal Associates 16 / 32

03 / Daily care

Comfortable movement
can help glucose.

If your obstetric team agrees, start with something manageable.

10–15 minutes of walking after a meal
is one practical starting option.

Choose what fits

Walking, swimming, or suitable prenatal activity.

Keep it comfortable

You should be able to hold a conversation.

Your activity plan depends on your pregnancy and any restrictions.

[1] ADA pregnancy care · 2026 [3] ACOG GDM guidance
OpenMFM · Atlanta Perinatal Associates 17 / 32

03 / Daily care

Repeated high readings
mean the plan needs adjusting.

Needing medication is not a failure.

  1. 01

    Notice

    Is fasting glucose high? Is one meal repeatedly above target?

  2. 02

    Share

    Send readings on the schedule your team gives you.

  3. 03

    Adjust

    Review food, timing, and medication needs together.

Do not wait for the next routine visit if readings remain above your agreed limits.

Follow-up and escalation
Review commonly occurs within about 1–2 weeks of starting nutrition therapy, sooner with marked elevations or advancing gestation. There is no universal percentage of elevated readings that mandates medication. Establish individualized call thresholds and sick-day instructions.
[1] ADA pregnancy care · 2026 [3] ACOG GDM guidance
OpenMFM · Atlanta Perinatal Associates 18 / 32

04 / Medication

Insulin can target
the times glucose is high.

Insulin is the preferred medication in ADA and ACOG guidance when lifestyle measures are not enough.

Fasting elevations

Background insulin can address overnight glucose.

After-meal elevations

Mealtime insulin can address a specific meal.

Your team teaches the dose, timing, injection technique, and low-glucose plan.

Clinician context
Insulin does not cross the placenta in clinically significant amounts. Regimens and titration depend on the glucose pattern, gestational age, weight, meals, and hypoglycemia risk. Needs can change as pregnancy progresses. Do not use a generic starting dose as an individual prescription.
[1] ADA pregnancy care · 2026 [3] ACOG GDM guidance
OpenMFM · Atlanta Perinatal Associates 19 / 32

04 / Medication

Discuss the tradeoffs
of medication choices.

An oral medicine may be considered after counseling.

Metformin

Crosses the placenta. Some patients still need insulin; long-term offspring outcomes remain a consideration.

Glyburide

Generally not a first-line choice because of less favorable newborn outcomes.

Tell your team about cost, access, injection concerns, and side effects.

Why guideline recommendations differ
ADA/ACOG prefer insulin. SMFM’s statement, reaffirmed in 2024, considers metformin a reasonable first-line alternative and notes that about half may still require insulin. The difference reflects how experts weigh the evidence. Renal function and other contraindications matter.
[1] ADA pregnancy care · 2026 [3] ACOG GDM guidance [8] SMFM medication statement
OpenMFM · Atlanta Perinatal Associates 20 / 32

04 / Medication

Know how to respond
to low glucose.

Shakiness, sweating, hunger, or confusion can be warning signs.

  1. 01

    Below 70 mg/dL

    If awake and able to swallow: take 15 g of fast-acting carbohydrate.

  2. 02

    Wait 15 minutes

    Recheck. Repeat if still below 70 mg/dL.

  3. 03

    After recovery

    Follow your meal/snack plan and tell your team about the low.

If unable to swallow, unconscious, or having a seizure: no food by mouth. Use prescribed glucagon and call emergency services.

Examples and safety
Examples of 15 g carbohydrate include about 4 oz (½ cup) regular juice or glucose tablets according to their label. Severe confusion or inability to self-treat requires another person’s help. Your diabetes team may individualize this plan.
[10] CDC low-glucose treatment
OpenMFM · Atlanta Perinatal Associates 21 / 32

05 / Pregnancy & birth

Your baby’s testing plan
depends on the whole pregnancy.

Ultrasound estimates growth. Other tests assess fetal well-being.

Diet-controlled GDM

Routine extra testing is not automatically needed in every uncomplicated pregnancy.

Medication or other concerns

Fetal testing is often considered around 32 weeks; timing and frequency vary.

Blood pressure, glucose control, growth, and other conditions can change the plan.

What the tests mean
NST (nonstress test) records the fetal heart rate. BPP (biophysical profile) combines ultrasound observations, sometimes with an NST. ACOG suggests considering once- or twice-weekly testing from 32 weeks for medication-controlled GDM, and twice weekly with poor control. Growth scan timing is individualized; estimated weight has uncertainty.
[3] ACOG GDM guidance [9] ACOG fetal surveillance
OpenMFM · Atlanta Perinatal Associates 22 / 32

05 / Pregnancy & birth

Well-controlled GDM does not
automatically mean early birth.

Typical delivery windows when there are no other complications:

Diet-controlled · A1GDM 39w0d–40w6d
Medication-controlled · A2GDM 39w0d–39w6d

Poor control or another complication needs a separate, individualized timing decision.

How to interpret these windows
w = weeks; d = days. Diet-controlled GDM alone does not require delivery before 39 weeks; expectant management up to 40w6d may be appropriate with indicated surveillance. These windows are not a promise that every pregnancy can safely wait.
[3] ACOG GDM guidance
OpenMFM · Atlanta Perinatal Associates 23 / 32

05 / Pregnancy & birth

A very large estimated baby
changes the birth discussion.

GDM alone does not mean you need a cesarean birth.

≥4,500 g estimated fetal weight with diabetes:
discuss the option of planned cesarean birth.

Ultrasound weight estimates are imperfect. Discuss benefits, risks, and your preferences.

[3] ACOG GDM guidance
OpenMFM · Atlanta Perinatal Associates 24 / 32

05 / Pregnancy & birth

Glucose checks continue
through birth.

Your care team plans for both you and your baby.

During labor

Your glucose is checked. Insulin or fluids may be adjusted under the hospital’s protocol.

After birth

Your baby’s glucose is checked. Early feeding and additional treatment may be needed.

Ask what to expect if your baby needs extra monitoring.

Hospital care varies
Frequency and maternal intrapartum glucose targets vary by hospital protocol. Newborn screening and treatment depend on symptoms, age after birth, glucose results, and pediatric guidance. Feeding helps but does not guarantee prevention of hypoglycemia.
[1] ADA pregnancy care · 2026 [3] ACOG GDM guidance
OpenMFM · Atlanta Perinatal Associates 25 / 32

06 / After birth

Insulin needs usually fall
quickly after delivery.

Once the placenta is delivered, much of pregnancy’s insulin resistance falls.

  1. 01

    Reassess

    Check glucose after delivery.

  2. 02

    Review medication

    GDM-only medication is often stopped under supervision.

  3. 03

    Follow persistent highs

    Ongoing high glucose needs a diabetes evaluation and treatment plan.

Do not assume glucose has returned to normal without follow-up.

[1] ADA pregnancy care · 2026
OpenMFM · Atlanta Perinatal Associates 26 / 32

06 / After birth

Book your glucose test
for 4–12 weeks after birth.

Before leaving the hospital, ask who will order the test and review the result.

75 g fasting, 2-hour oral glucose tolerance test
at 4–12 weeks postpartum.

A1C alone is less suitable this soon after birth.

Postpartum testing context
Blood loss and pregnancy-related red cell changes can affect A1C. The OGTT uses nonpregnancy criteria postpartum. ACOG also recognizes testing during the delivery admission as an alternative in some settings; coordinate interpretation and follow-up with the care team.
[1] ADA pregnancy care · 2026 [4] ACOG screening update · 2024
OpenMFM · Atlanta Perinatal Associates 27 / 32

06 / After birth

Follow-up protects
your future health.

A history of GDM raises your future risk of type 2 diabetes.

  1. 01

    Every 1–3 years

    Repeat diabetes screening, even if the postpartum result was normal.

  2. 02

    Between pregnancies

    Keep sustainable food and activity habits; request feeding support if desired.

  3. 03

    Before another pregnancy

    Check for diabetes and plan care before conception.

Breastfeeding has health benefits, but it does not replace diabetes screening.

[1] ADA pregnancy care · 2026
OpenMFM · Atlanta Perinatal Associates 28 / 32

07 / Take home

Five actions
worth remembering.

You do not have to manage GDM alone.

  1. Complete the right diagnostic test.
  2. Know your fasting and postmeal targets.
  3. Share patterns and ask for help early.
  4. Follow your individualized pregnancy and birth plan.
  5. Keep your postpartum glucose appointment.

A workable plan matters more than blame or perfection.

[1] ADA pregnancy care · 2026 [2] ADA diagnosis · 2026 [3] ACOG GDM guidance [4] ACOG screening update · 2024
OpenMFM · Atlanta Perinatal Associates 29 / 32

07 / Evidence

Strong evidence guides care.
Some questions remain.

Guidelines combine research with clinical judgment.

Well supported

Treating diagnosed GDM reduces important growth and birth complications.

Still being studied

Who benefits most from early treatment or CGM in GDM; long-term effects of fetal medication exposure.

Experts differ

How to weigh insulin and metformin as initial medication choices.

Ask how the evidence applies to your own pregnancy.

Research context
TOBOGM found a modest reduction in a composite neonatal outcome with early treatment in an at-risk population, without a material effect on pregnancy-related hypertension. This does not establish one early-pregnancy treatment threshold for everyone. CGM studies differ in populations, devices, and outcomes.
[5] ACHOIS randomized trial [6] Mild GDM randomized trial [8] SMFM medication statement [11] TOBOGM early-treatment trial
OpenMFM · Atlanta Perinatal Associates 30 / 32

07 / Your next conversation

Ask for a plan
you can use.

Bring these questions to your MFM or obstetric team.

This education supports a conversation with your care team; it does not replace individualized medical advice.

[1] ADA pregnancy care · 2026 [3] ACOG GDM guidance
OpenMFM · Atlanta Perinatal Associates 31 / 32

08 / Sources

Evidence you can
follow back to its source.

Guidelines, randomized trials, and patient safety resources. Links open in a new tab.

  1. ADA pregnancy care · 2026

    American Diabetes Association Professional Practice Committee for Diabetes. 15. Management of Diabetes in Pregnancy: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1):S321–S338.

  2. ADA diagnosis · 2026

    American Diabetes Association Professional Practice Committee for Diabetes. 2. Diagnosis and Classification of Diabetes: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1):S27–S49.

  3. ACOG GDM guidance

    American College of Obstetricians and Gynecologists. ACOG Practice Bulletin No. 190: Gestational Diabetes Mellitus. Obstet Gynecol. 2018;131:e49–e64.

  4. ACOG screening update · 2024

    American College of Obstetricians and Gynecologists. ACOG Clinical Practice Update: Screening for Gestational and Pregestational Diabetes in Pregnancy and Postpartum. Obstet Gynecol. 2024;144:e20–e23.

  5. ACHOIS randomized trial

    Crowther CA, Hiller JE, Moss JR, et al. Effect of treatment of gestational diabetes mellitus on pregnancy outcomes. N Engl J Med. 2005;352:2477–2486.

  6. Mild GDM randomized trial

    Landon MB, Spong CY, Thom E, et al. A multicenter, randomized trial of treatment for mild gestational diabetes. N Engl J Med. 2009;361:1339–1348.

  7. USPSTF screening

    US Preventive Services Task Force. Screening for Gestational Diabetes: US Preventive Services Task Force Recommendation Statement. JAMA. 2021;326:531–538.

  8. SMFM medication statement

    Society for Maternal-Fetal Medicine Publications Committee. SMFM Statement: Pharmacological treatment of gestational diabetes. Am J Obstet Gynecol. 2018;218:B2–B4. Reaffirmed 2024.

  9. ACOG fetal surveillance

    American College of Obstetricians and Gynecologists. Indications for Outpatient Antenatal Fetal Surveillance. Committee Opinion No. 828. Obstet Gynecol. 2021;137:e177–e197.

  10. CDC low-glucose treatment

    Centers for Disease Control and Prevention. Treatment of Low Blood Sugar (Hypoglycemia). May 15, 2024. Accessed October 28, 2026.

  11. TOBOGM early-treatment trial

    Simmons D, Immanuel J, Hague WM, et al. Treatment of gestational diabetes mellitus diagnosed early in pregnancy. N Engl J Med. 2023;388:2132–2144.

Updated October 28, 2026 · OpenMFM Presentation Standard v1.0

Sources & further reading

Links open in a new tab. Updated October 28, 2026.

  1. ADA pregnancy care · 2026

    American Diabetes Association Professional Practice Committee for Diabetes. 15. Management of Diabetes in Pregnancy: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1):S321–S338.

  2. ADA diagnosis · 2026

    American Diabetes Association Professional Practice Committee for Diabetes. 2. Diagnosis and Classification of Diabetes: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1):S27–S49.

  3. ACOG GDM guidance

    American College of Obstetricians and Gynecologists. ACOG Practice Bulletin No. 190: Gestational Diabetes Mellitus. Obstet Gynecol. 2018;131:e49–e64.

  4. ACOG screening update · 2024

    American College of Obstetricians and Gynecologists. ACOG Clinical Practice Update: Screening for Gestational and Pregestational Diabetes in Pregnancy and Postpartum. Obstet Gynecol. 2024;144:e20–e23.

  5. ACHOIS randomized trial

    Crowther CA, Hiller JE, Moss JR, et al. Effect of treatment of gestational diabetes mellitus on pregnancy outcomes. N Engl J Med. 2005;352:2477–2486.

  6. Mild GDM randomized trial

    Landon MB, Spong CY, Thom E, et al. A multicenter, randomized trial of treatment for mild gestational diabetes. N Engl J Med. 2009;361:1339–1348.

  7. USPSTF screening

    US Preventive Services Task Force. Screening for Gestational Diabetes: US Preventive Services Task Force Recommendation Statement. JAMA. 2021;326:531–538.

  8. SMFM medication statement

    Society for Maternal-Fetal Medicine Publications Committee. SMFM Statement: Pharmacological treatment of gestational diabetes. Am J Obstet Gynecol. 2018;218:B2–B4. Reaffirmed 2024.

  9. ACOG fetal surveillance

    American College of Obstetricians and Gynecologists. Indications for Outpatient Antenatal Fetal Surveillance. Committee Opinion No. 828. Obstet Gynecol. 2021;137:e177–e197.

  10. CDC low-glucose treatment

    Centers for Disease Control and Prevention. Treatment of Low Blood Sugar (Hypoglycemia). May 15, 2024. Accessed October 28, 2026.

  11. TOBOGM early-treatment trial

    Simmons D, Immanuel J, Hague WM, et al. Treatment of gestational diabetes mellitus diagnosed early in pregnancy. N Engl J Med. 2023;388:2132–2144.