Understanding Gestational Diabetes

A Complete Guide for You and Your Baby

You Are Not Alone

Gestational diabetes is more common than you might think, and you have a whole community behind you.

9–15%

of all pregnancies worldwide are affected by gestational diabetes.

Rates have nearly doubled from 2006 to 2017.

It is not your fault.

This is a natural response to pregnancy hormones. With the right care, most women have healthy pregnancies and healthy babies.

The Mechanism

What Is Gestational Diabetes?

Gestational diabetes (GDM) is high blood sugar that develops during pregnancy, usually first detected between 24 and 28 weeks.

Insulin is the "Key": Ideally, insulin unlocks your cells so sugar from food can enter and give you energy.

The Lock is Stuck: Pregnancy hormones make your body more resistant to insulin. In GDM, your pancreas can't make enough extra insulin to overcome this resistance.

The Science Made Simple

Pregnancy hormones naturally increase insulin resistance to help your baby grow.

01

The Placenta's Role

During pregnancy, your placenta produces hormones like placental lactogen and cortisol. These naturally make your cells resist insulin so that plenty of glucose stays in your blood for the baby.

02

Normal Response

In a typical pregnancy, your pancreas compensates for this resistance by working harder. It produces up to 30% more insulin to keep your blood sugar levels stable.

03

What Happens in GDM

In gestational diabetes, the pancreas cannot keep up with the high demand. This is called beta-cell dysfunction. The result is blood sugar levels that rise higher than normal.

Who Is at Higher Risk?

Certain factors increase your chances of developing GDM

History

Family history of diabetes (parent or sibling)

Previous pregnancy with GDM

Previously had a large baby (>9 lbs / 4,000 g)

Polycystic ovary syndrome (PCOS)

Body & Lifestyle

BMI ≥ 25 kg/m² before pregnancy (≥ 23 in Asian Americans)

Physical inactivity

Age 35 or older

Hypertension or heart disease

Background

Hispanic / Latina

African American

Native American

Asian American

Pacific Islander

Important: More than half of women with GDM have none of these risk factors. That is why your doctor screens everyone.

How Will I Be Tested?

Screening typically happens between 24 and 28 weeks using a two-step approach.

1

Step 1

The Glucose Challenge Test (GCT)

You drink a sweet liquid containing 50 grams of glucose.
Blood is drawn 1 hour later.
No fasting required — you can eat normally before this test.
If your result is ≥ 130–140 mg/dL, you will proceed to Step 2.

2

Step 2

The 3-Hour Glucose Tolerance Test (GTT)

Fasting is required (usually overnight).
You drink a stronger liquid with 100 grams of glucose.
Blood is drawn 4 times: Fasting, 1 hour, 2 hours, and 3 hours.
Gestational diabetes is diagnosed if 2 or more values are elevated.

Understanding Your Diagnosis

Not all GDM is the same — your type guides your treatment plan.

A1GDM

Diet-Controlled

Your blood sugar levels stay within the target range using healthy eating and physical activity alone.

Treatment Plan:

Medical Nutrition Therapy
Daily Exercise
Glucose Monitoring

A2GDM

Medication-Controlled

Your blood sugar requires medication (like insulin or metformin) to stay consistently within the safe range.

Treatment Plan:

All Lifestyle Changes
PLUS Medication
Additional Fetal Monitoring

Did you know? Most women start with A1GDM. About 1 in 3 will eventually need medication (A2GDM). This classification also guides decisions about when you will deliver.

Why Blood Sugar Control Matters

High blood sugar crosses the placenta and affects your baby's growth.

What Happens Inside

Glucose Transfer

When your blood sugar is high, extra glucose crosses the placenta to your baby.

Insulin Response

Your baby's pancreas responds by making extra insulin, which acts like a growth hormone.

Macrosomia

This can cause your baby to grow larger than normal (estimated fetal weight > 4,000 g).

Potential Risks

Large Baby (Macrosomia): Can lead to a harder delivery and possible shoulder injury.
Neonatal Hypoglycemia: Low blood sugar immediately after birth.
Breathing difficulties or jaundice at birth.
Higher risk of obesity and diabetes later in life.

What Are the Risks for Me?

GDM affects your health too — both now and in the future.

During This Pregnancy

Preeclampsia

Higher chance of developing high blood pressure during pregnancy.

Cesarean Delivery

Increased likelihood of needing a C-section due to baby size.

Polyhydramnios

Risk of having too much amniotic fluid, which can complicate delivery.

After Delivery

50–70%

of women with GDM develop Type 2 Diabetes within 10 years.

2x

Higher lifetime risk of cardiovascular disease.

76%

Higher risk of GDM recurrence in a future pregnancy.

The Silver Lining: A GDM diagnosis is your body's early warning system. Acting now can protect your long-term health.

Your Blood Sugar Goals

Keeping your levels in this range helps protect your baby.

Fasting

First thing in the morning

< 95 mg/dL

1 Hour After Meal

Start timing from first bite

< 140 mg/dL

2 Hours After Meal

Start timing from first bite

< 120 mg/dL

Checking Your Blood Sugar

Two ways to monitor your levels: Fingersticks and CGMs.

Fingerstick

The Gold Standard

Most Accurate: Measures glucose directly from your blood (capillary blood).
Required for Diagnosis: Treatment decisions are primarily based on these numbers.
When to Test: Typically fasting (first thing in the morning) and 1 or 2 hours after the start of each meal.

CGM

Continuous Monitor

Measures Fluid, Not Blood: Reads glucose in the fluid between cells (interstitial fluid).
The "Lag" Time: Readings can be 15–20 minutes behind your actual blood sugar.
Great for Trends: Helps you see how specific foods affect you in real-time.

Important: If your CGM reading doesn't match how you feel, or if it shows a very low/high number, always double-check with a fingerstick before treating.

Medical Nutrition Therapy

Food Is Your First Medicine

You don't need to eliminate carbohydrates. The goal is to choose the right type and amount to keep blood sugar stable.

Eat Consistency

Eat every 2–3 hours. Aim for 3 meals and 2–3 snacks daily to prevent sugar spikes and drops.
Pair Your Carbs

Never eat a "naked" carb. Always pair carbohydrates with protein or healthy fats to slow digestion.
Focus on Quality

Choose complex carbohydrates (whole grains, veggies) over simple sugars (juice, sweets).

Smart Food Choices

Focus on quality carbohydrates that digest slowly to keep blood sugar stable.

Choose More Often

Whole Grains Brown rice, quinoa, oats, whole wheat bread.
Non-Starchy Vegetables Spinach, broccoli, peppers, zucchini, leafy greens.
Legumes & Beans Lentils, chickpeas, black beans (high in fiber).
Whole Fruits Berries, apples with skin, citrus (in moderation).
Healthy Proteins & Fats Nuts, seeds, avocado, eggs, lean meats.

Limit or Avoid

Refined Grains White bread, white rice, regular pasta, flour tortillas.
Sugary Drinks Soda, fruit juice, sweet tea, flavored coffees.
Processed Snacks Chips, crackers, pretzels, granola bars.
Sweets & Desserts Cakes, cookies, pastries, ice cream.
Sweetened Breakfasts Sugary cereals, instant oatmeal packets, flavored yogurt.

Natural Blood Sugar Control

Exercise Is Powerful Medicine

When you move, your muscles use glucose for energy, naturally lowering your blood sugar without the need for extra insulin. Aim for 30 minutes of moderate activity most days of the week.

Walking

Swimming

Prenatal Yoga

The "Talk Test"

Exercise should be moderate, not exhausting. You should be able to carry on a normal conversation while exercising. If you are too breathless to talk, slow down.

When Medication Is Needed

If diet and exercise aren't enough, medication is a safe tool to protect your baby.

Insulin

Gold Standard

Preferred by Experts: ACOG and SMFM recommend insulin as the first-line treatment.
Does NOT Cross the Placenta: It stays in your blood and does not reach the baby.
Highly Effective: Can be precisely dosed to control fasting and post-meal numbers.
Taken as a daily injection (pen or syringe).

Metformin

Alternative

Oral Option: A pill taken with meals, which some patients prefer over needles.
Crosses the Placenta: The medication does reach the baby, though studies show it is generally safe.
When It's Used: Often prescribed if insulin is declined or not an option.
May cause stomach upset initially.

Remember: Needing medication is not a failure. It is simply a biological necessity for some placentas to ensure your baby stays healthy.

Watching Your Baby Grow

We use extra monitoring to ensure your baby is safe and your placenta is working well.

Growth Ultrasounds

What We Check

We measure the baby's head, belly, and leg bone to estimate their weight. We also check the amniotic fluid levels.

The Goal

To spot macrosomia (large baby) or excessive fluid early, which helps us plan a safe delivery.

Typical Schedule

Usually performed around 32 weeks and 36 weeks.

Fetal Surveillance

The Tests

NST (Non-Stress Test): Monitors baby's heart rate for 20 mins.
BPP (Biophysical Profile): An ultrasound that checks movement, breathing, tone, and fluid.

The Goal

To confirm the placenta is providing enough oxygen and nutrients. A "reactive" test means a happy baby.

Typical Schedule

Often starts at 32 weeks (especially if on medication) and is done 1–2 times per week.

Note: If your blood sugar is well-controlled by diet alone (A1GDM), you may not need weekly testing until 40 weeks.

When Will I Deliver?

Timing depends on your blood sugar control and medication use.

Diet-Controlled (A1GDM)

Expectant Management

39–40 weeks

If your blood sugar is well-controlled with diet alone and your baby is doing well, you can typically wait for labor to start naturally up to your due date. Recommendation: Delivery by 40w6d (avoiding >41w when possible).

Medication-Controlled (A2GDM)

Scheduled Delivery

39 weeks

If you require medication, the placenta may age faster. Recommendation: Induction is typically scheduled between 39w0d–39w6d to balance maturity and risk reduction.

Why might I deliver earlier? (37–38 weeks)

Earlier delivery may be recommended for poor glucose control, preeclampsia, or concerns about fetal growth or fluid levels.

During Labor and Delivery

Our goal is to keep blood sugar stable to prevent hypoglycemia in the baby.

For You

Frequent Checks: We will check your blood sugar every 1–2 hours during active labor.
The Goal: We aim to keep your levels between 70 and 110 mg/dL.
Insulin Changes: Active labor naturally lowers blood sugar. If you are on insulin, we typically stop or drastically reduce it once labor begins.

For Baby

Immediate Check: Your baby will have a heel stick to check blood sugar shortly after birth.
Watch for Lows: We monitor for hypoglycemia (low blood sugar) for the first 12–24 hours.
Treatment: Early breastfeeding or formula feeding is the best prevention. Glucose gel may be used if levels are low.

Why does baby's sugar drop?

Once the umbilical cord is cut, the baby's high sugar supply from you stops instantly. However, their pancreas may still be pumping out extra insulin, causing their own blood sugar to drop rapidly.

Breastfeeding and GDM

Breastfeeding is a powerful medical tool for long-term prevention.

For You

Improves Insulin Sensitivity Helps your body use insulin better after birth.
Supports Weight Loss Burns extra calories to help return to a healthy weight.
Reduces Diabetes Risk Lowers lifetime risk of Type 2 Diabetes.

For Baby

Regulates Blood Sugar Stabilizes baby's glucose after birth.
Prevents Obesity Lowers risk of childhood obesity.
Long-Term Protection Reduces later-life diabetes risk.

50%

Breastfeeding ≥3 months can cut your Type 2 Diabetes risk by up to 50%.

Your Postpartum Check-Up

Gestational diabetes usually goes away after birth, but we must verify it.

The Timing

Schedule your test between 4 and 12 Weeks after your delivery.

The Test

The 75g 2-Hour Oral Glucose Tolerance Test. Fasting + 2-Hour Draw

Why not just check A1C?

The Hemoglobin A1C test is not recommended at this visit. Blood loss during delivery and rapid cell turnover make the A1C inaccurate this soon postpartum. The 2-hour drink test is the only accurate way to screen right now.

If Normal

Re-screen every 1–3 years

If Prediabetes

Lifestyle changes + Metformin

If Diabetes

Referral to Endocrinology

Reducing Your Long-Term Risk

Your Action Plan for a Healthy Future

Did you know? Women with GDM have a 7-fold increased risk of developing Type 2 Diabetes later in life.

Healthy Weight

Returning to your pre-pregnancy weight is key. Losing just 5–7% of your body weight can significantly lower your risk of diabetes.

Nutrition

Don't stop your healthy habits now. Continue choosing complex carbs, lean proteins, and veggies as a permanent lifestyle change.

Active Living

Aim for at least 150 minutes of moderate activity per week. That's just 30 minutes a day, 5 days a week.

Ongoing Screening

Don't skip your check-ups. Early detection is your best protection.

Test Every 1–3 Years

Your Baby's Long-Term Health

Understanding how your pregnancy affects your child's future metabolism.

Metabolic Programming

The Environment Matters: High blood sugar in the womb can "program" your baby's metabolism to store fat more easily.

The Risk: Babies born to moms with uncontrolled GDM have a higher risk of childhood obesity and developing Type 2 Diabetes themselves later in life.

Breaking the Cycle

Your Control is Key: By keeping your blood sugar in range now, you are actively lowering these risks for your child.

After Birth: Breastfeeding, a healthy family diet, and keeping your child active are powerful ways to continue this protection and ensure a healthy future.

"You are not just managing a condition; you are changing your family's health history."

Your Care Team

You are not alone. A team of experts is here to support you and your baby.

OB/GYN Provider

Primary Care & Delivery

Manages your overall pregnancy care, monitors your blood pressure, and delivers your baby.

Maternal-Fetal Medicine

High-Risk Specialist

Performs detailed ultrasounds, interprets fetal monitoring, and manages complex blood sugar issues.

Registered Dietitian

Nutrition Expert

Helps you create a personalized meal plan that fits your lifestyle while keeping blood sugar stable.

Diabetes Educator

Teacher & Coach

Teaches you how to use your glucose meter, interpret the numbers, and administer insulin if needed.

We communicate regularly to ensure you and your baby receive the best coordinated care.

Questions to Ask Your Doctor

Be an active partner in your care. Bring this list to your next visit.

Reporting Numbers

How often and by what method (portal, phone, logbook) should I send you my blood sugar logs?

Specific Targets

What are my specific goals for fasting and post-meal numbers? Should I test 1 or 2 hours after eating?

When to Call

At what blood sugar level should I call the office immediately? What should I do if I have a "low"?

Baby Monitoring

Will I need extra growth ultrasounds or non-stress tests (NSTs)? When do those start?

Delivery Plan

How does my diagnosis affect my delivery timing? Will I need to be induced?

Postpartum

When should I schedule my 2-hour glucose test after the baby is born?

Tip: Take a picture of your glucose log or bring your meter to every appointment.

Key Takeaways

Five things to remember for a healthy pregnancy.

01

It's Not Your Fault

Gestational diabetes is caused by placental hormones blocking your insulin. It is not caused by something you did wrong.

02

Food is Medicine

Eating complex carbs paired with protein and healthy fats is the most powerful way to control your blood sugar.

03

Movement Matters

A 10–15 minute walk after meals helps your muscles use up glucose naturally, lowering your numbers.

04

Medication is Safe

If diet isn't enough, insulin or metformin are safe tools to protect your baby from high sugar levels.

05

Follow Up Postpartum

Don't forget your 2-hour glucose test 4–12 weeks after delivery to ensure your diabetes has resolved.

A Final Note

You've Got This

Gestational diabetes is a challenge, but it is temporary. Every healthy meal, every walk, and every fingerstick is an act of love.

You are doing an amazing job for your baby.

Questions? Call us: (555) 012-3456

Patient Portal: www.myhealthportal.com

Sources: ACOG Practice Bulletin No. 190 (Gestational Diabetes Mellitus), SMFM Consult Series #58, ADA Standards of Care.