Gestational DiabetesDiabetes During Pregnancy

Gestational diabetes is a type of diabetes that develops during pregnancy in women who didn't have diabetes before. It affects about 6-9% of pregnancies and usually appears in the second or third trimester. While it requires careful management, most women with gestational diabetes have healthy pregnancies and babies.

What Is Gestational Diabetes?

During pregnancy:

• The placenta produces hormones that help the baby develop
• These hormones can also block insulin in the mother's body
• This is called insulin resistance
• All pregnant women have some insulin resistance in late pregnancy
• Gestational diabetes occurs when the pancreas can't produce enough extra insulin to overcome this resistance

Risk Factors

Risk Factor	Details
Overweight or obesity	BMI of 25 or higher before pregnancy
Age	Over 25 years old
Family history	Parent or sibling with Type 2 diabetes
Previous gestational diabetes	Had it in a prior pregnancy
Previous large baby	Baby weighed over 9 pounds
Prediabetes	Elevated blood sugar before pregnancy
PCOS	Polycystic ovary syndrome
Ethnicity	Higher in African American, Hispanic, Native American, Asian American, Pacific Islander

Note: Many women with gestational diabetes have no known risk factors.

Screening and Diagnosis

Most pregnant women are tested between 24-28 weeks:

One-Step Approach (75g OGTT)

• Fast overnight
• Blood drawn fasting
• Drink 75g glucose solution
• Blood drawn at 1 hour and 2 hours
• Diagnosis if any one value is elevated

Two-Step Approach

Step 1: Glucose Challenge Test (50g)

• No fasting required
• Drink 50g glucose solution
• Blood drawn after 1 hour
• If result is 130-140 mg/dL or higher, proceed to Step 2

Step 2: Oral Glucose Tolerance Test (100g)

• Fast overnight
• Blood drawn fasting, then at 1, 2, and 3 hours after drinking 100g glucose
• Diagnosis if two or more values are elevated

Diagnostic Thresholds (100g OGTT)

Timing	Threshold
Fasting	95 mg/dL or higher
1 hour	180 mg/dL or higher
2 hours	155 mg/dL or higher
3 hours	140 mg/dL or higher

Risks if Untreated

Risks for Baby

• Macrosomia - Large birth weight (over 9 lbs), can cause difficult delivery
• Hypoglycemia after birth - Baby's blood sugar drops after delivery
• Preterm birth
• Breathing problems at birth
• Jaundice
• Higher risk of obesity and Type 2 diabetes later in life

Risks for Mother

• Preeclampsia - High blood pressure during pregnancy
• Cesarean delivery - More likely with large baby
• Future Type 2 diabetes - 50% develop within 5-10 years
• Gestational diabetes in future pregnancies

Good news: With proper management, these risks are significantly reduced.

Managing Gestational Diabetes

Blood Sugar Targets

Timing	Target
Fasting	95 mg/dL or less
1 hour after meal	140 mg/dL or less
2 hours after meal	120 mg/dL or less

Diet

The cornerstone of gestational diabetes management:

• Spread carbs throughout the day - 3 moderate meals + 2-3 snacks
• Limit carbs at breakfast - Insulin resistance is highest in morning
• Choose complex carbs - Whole grains, vegetables, legumes
• Pair carbs with protein - Slows glucose release
• Avoid sugary drinks and sweets
• Don't skip meals - Keeps blood sugar stable

Physical Activity

• 30 minutes of moderate activity most days
• Walking after meals is especially helpful
• Swimming and prenatal yoga are good options
• Always check with your doctor first

Blood Sugar Monitoring

• Test 4 times daily typically (fasting + after each meal)
• Record all readings to share with your care team
• Note what you ate if readings are high

Medication

If diet and exercise don't achieve targets:

• Insulin - The most common medication, safe for baby
• Metformin - May be used in some cases
• Glyburide - Sometimes used, though less preferred now

About 10-20% of women with gestational diabetes need medication.

Pregnancy Monitoring

Extra monitoring ensures baby's health:

• More frequent prenatal visits
• Growth ultrasounds - Check baby's size
• Non-stress tests - Monitor baby's heart rate
• Kick counts - Track baby's movements

Delivery

• Most women can deliver vaginally
• Timing depends on blood sugar control and baby's size
• May be induced at 39-40 weeks if well-controlled
• Earlier delivery may be recommended if complications
• C-section may be needed for very large babies
• Blood sugar monitored during labor

After Delivery

Immediate

• Gestational diabetes usually resolves after delivery
• Blood sugar levels typically return to normal quickly
• Baby's blood sugar will be monitored
• Breastfeeding is encouraged—helps both mother and baby

Long-Term Follow-Up

• Postpartum glucose test at 4-12 weeks after delivery
• Screen for diabetes every 1-3 years for life
• Lifestyle changes can prevent or delay Type 2 diabetes

Reducing Future Diabetes Risk

After gestational diabetes, reduce your Type 2 risk:

• Lose pregnancy weight if needed
• Stay physically active - 150 minutes/week
• Eat a healthy diet - Whole foods, limited refined carbs
• Breastfeed - Improves insulin sensitivity
• Get tested regularly - Catch prediabetes early