Gestational Diabetes

Gestational diabetes is diagnosed through the oral glucose tolerance test (OGTT), which is usually performed between the 24th and 28th weeks of pregnancy.

In women with risk factors, the test may be done earlier, as early as the first trimester.

Normal values:

• Fasting: < 92 mg/dl
• 1 hour later: < 180 mg/dl
• 2 hours later: < 153 mg/dl

If one or more values exceed these limits, the diagnosis of gestational diabetes is established.

Uncontrolled gestational diabetes—that is, gestational diabetes that is not properly treated—can affect both the mother and the fetus.

For the fetus:

• Macrosomia—excessive weight gain. The fetus receives excess glucose and responds by producing additional insulin, resulting in increased fat deposition. This can make delivery more difficult and increase the risk of cesarean section.
• Neonatal hypoglycemia—after birth, the newborn may have low blood sugar due to the increased insulin production developed in utero.
• Increased risk of respiratory distress—especially in preterm birth.
• Long-term—children of mothers with uncontrolled gestational diabetes have an increased risk of obesity and type 2 diabetes in adulthood.

For the mother:

• Increased risk of preeclampsia
• Increased risk of cesarean section
• Increased risk of developing type 2 diabetes after pregnancy

A diagnosis of gestational diabetes does not mean that the pregnancy automatically becomes dangerous—it means that careful management is needed. And that management starts with nutrition.

Nutrition in gestational diabetes

The goal is not to eliminate carbohydrates, but to choose the right carbohydrates and distribute them properly throughout the day.

Basic principles:

• Small, frequent meals (3 main meals and 2–3 snacks)
• Preference for complex carbohydrates with a low glycemic index (whole grains, legumes, vegetables)
• Avoidance of simple sugars (soft drinks, juices, sweets, white bread)
• Adequate protein intake at every meal
• Avoiding a large amount of carbohydrates at breakfast

Blood sugar self-monitoring

In most cases, self-monitoring of blood sugar at home is recommended. This allows immediate evaluation of the response to diet and timely adjustments.

Physical activity

Mild exercise—such as walking for 20–30 minutes after meals—helps significantly with blood sugar control. It should always be discussed on an individual basis with the doctor.

Medication

In 15–20% of cases, diet alone is not sufficient to control blood sugar, and insulin is then required. Insulin is safe for the fetus and is the first-line medication for gestational diabetes.

In a pregnancy affected by diabetes, monitoring becomes more intensive:

• More frequent visits and blood sugar measurements
• Growth ultrasounds to monitor fetal weight—so that possible macrosomia can be detected early
• Flow Doppler if there are additional risk factors
• Careful planning of the timing and mode of delivery

In the vast majority of cases, gestational diabetes resolves after childbirth. Blood sugar levels return to normal within days or weeks.

However, there are two important things you should know:

First, women who had gestational diabetes have an increased risk of developing type 2 diabetes later in life (up to 50% over the next 10 years). For this reason, repeat testing with an oral glucose tolerance test is recommended 6–12 weeks after childbirth and then regular screening every 1–3 years.

Second, the risk of recurrence in a future pregnancy is high (about 30–50%). Proper information and early monitoring from the beginning of the next pregnancy are essential.