Gestational Diabetes: Risk Factors, Symptoms and When to Get Tested

Pregnancy brings many changes to the body, including changes in how it uses sugar for energy. For some women, blood sugar levels become higher than normal during pregnancy, leading to a condition called gestational diabetes mellitus (GDM).

Gestational diabetes can develop even if you have never had diabetes before. What makes it particularly important is that it often does not cause noticeable symptoms, which is why routine testing during pregnancy plays an important role in detecting it.

The good news is that gestational diabetes can usually be managed with appropriate medical care, nutrition, physical activity and, when needed, medication.

So, who is more likely to develop gestational diabetes? What symptoms should you look out for? And when should you get tested?

Let’s take a closer look.

What Is Gestational Diabetes?

Gestational diabetes is high blood glucose first recognised during pregnancy in a woman who did not previously have diabetes.

During pregnancy, the body naturally becomes more resistant to insulin. Insulin helps move glucose from the blood into the body's cells, where it can be used for energy.

As pregnancy progresses, some women may not produce enough insulin to overcome this increased insulin resistance. As a result, blood glucose levels can rise.

Gestational diabetes is different from diabetes that existed before pregnancy, although sometimes high blood glucose detected early in pregnancy may indicate previously undiagnosed diabetes rather than typical gestational diabetes.

Why Does Gestational Diabetes Happen?

Pregnancy naturally changes the way the body handles glucose.

Hormones produced during pregnancy can make cells less responsive to insulin. This is a normal adaptation that helps ensure enough glucose is available to support the growing baby.

Most women are able to produce additional insulin to compensate.

When the body cannot produce enough insulin to keep blood glucose within the normal range, gestational diabetes can develop.

It is therefore not simply caused by eating too much sugar during pregnancy.

Several factors can influence the likelihood of developing it.

Who Is at Risk of Gestational Diabetes?

Gestational diabetes can occur in women without any obvious risk factors. However, certain factors may increase the likelihood.

1. Previous Gestational Diabetes

If you had gestational diabetes during an earlier pregnancy, you have a higher chance of developing it again.

This is one reason your doctor may recommend closer monitoring in a subsequent pregnancy.

2. Family History of Diabetes

Having a close family member with diabetes may increase your risk.

Your genetic background can influence how your body handles glucose and insulin.

3. Higher Pre-Pregnancy Weight

Being overweight or having obesity before pregnancy can increase the risk of gestational diabetes.

However, women at a healthy weight can develop GDM too.

4. Previous Baby With High Birth Weight

Having previously delivered a baby with a high birth weight can be associated with an increased risk of gestational diabetes in a later pregnancy.

5. Polycystic Ovary Syndrome / PMOS

Polycystic ovary syndrome, also referred to increasingly as polyendocrine metabolic ovarian syndrome (PMOS) in some newer terminology, is associated with insulin resistance and may increase the risk of gestational diabetes.

6. Increasing Maternal Age

The risk of gestational diabetes generally increases with maternal age.

However, age alone does not determine whether someone will develop GDM.

7. Previous Abnormal Blood Sugar

If you have previously been told that your blood sugar was higher than normal, your doctor may recommend earlier or additional testing during pregnancy.

8. Certain Ethnic or Population Backgrounds

Some populations have a higher prevalence of diabetes and gestational diabetes. This can influence how healthcare providers approach screening.

Importantly, risk factors are not a substitute for testing. Gestational diabetes can occur in women who have none of these factors.

What Are the Symptoms of Gestational Diabetes?

This is one of the most important things to understand:

Many women with gestational diabetes have no noticeable symptoms.

That is why you should not wait for symptoms before getting tested. WHO notes that gestational diabetes is generally identified through prenatal screening rather than reported symptoms.

When symptoms do occur, they may include:

• Increased thirst
• More frequent urination
• Unusual tiredness
• Blurred vision
• Increased hunger

However, these symptoms can also occur during a normal pregnancy.

So, symptoms alone cannot confirm or rule out gestational diabetes.

When Is Gestational Diabetes Tested?

The usual window for diagnosing gestational diabetes is between 24 and 28 weeks of pregnancy. WHO's antenatal-care guidance lists blood glucose testing for gestational diabetes during this period.

Depending on your medical history and risk factors, your doctor may recommend checking blood glucose earlier in pregnancy.

For example, earlier assessment may be considered if you:

• Had gestational diabetes in a previous pregnancy
• Have a history of diabetes
• Have significant risk factors for diabetes
• Have previously had abnormal blood glucose
• Have other clinical factors that concern your doctor

If early testing is normal, you may still need repeat testing later in pregnancy because gestational diabetes can develop as pregnancy progresses.

How Is Gestational Diabetes Diagnosed?

One commonly used test is an oral glucose tolerance test (OGTT).

Depending on the protocol used by your healthcare provider, you may be asked to:

1. Fast overnight before the test.
2. Have your fasting blood glucose measured.
3. Drink a glucose-containing solution.
4. Have your blood glucose measured at specified intervals afterward.

The test checks how your body responds to a controlled amount of glucose.

Different countries, healthcare systems and professional guidelines may use different screening and diagnostic approaches. Your doctor will follow the protocol appropriate for your pregnancy and clinical situation.

WHO's diagnostic criteria for a 75-g OGTT include fasting, 1-hour and 2-hour glucose measurements. Under WHO criteria, GDM can be diagnosed when one or more specified glucose values fall within the GDM range.

What Happens If You Are Diagnosed With Gestational Diabetes?

A diagnosis of gestational diabetes does not mean that your pregnancy cannot be healthy.

Your healthcare team may recommend:

Nutrition changes

You may be advised to adjust meal portions, carbohydrate choices, meal timing and overall nutrition.

The goal is not to stop eating carbohydrates completely but to create a balanced eating pattern that helps maintain healthy blood glucose levels.

Regular physical activity

If your pregnancy is otherwise uncomplicated and your doctor agrees, appropriate physical activity can support blood glucose control.

Walking after meals may be one simple option, but the right level of activity varies between women.

Blood glucose monitoring

Your doctor may ask you to check your blood glucose at specific times, such as before or after meals.

This helps determine whether lifestyle changes are controlling your blood sugar adequately.

Medication when needed

If blood glucose levels remain above the recommended range despite lifestyle measures, your doctor may prescribe medication.

Insulin may be recommended in some pregnancies, depending on blood glucose levels and the treatment approach used by your healthcare team.

Treatment is individualised. WHO's recommendations describe a stepped approach that can include nutritional counselling and physical activity, followed by glucose-lowering medication or insulin when necessary.

Why Does Gestational Diabetes Need to Be Managed?

High blood glucose during pregnancy can increase the risk of certain pregnancy and birth complications.

These can include:

• A baby growing larger than expected
• High blood pressure and pre-eclampsia
• Complications during delivery
• Newborn low blood sugar
• Other complications affecting the mother or baby

The risks depend on how high blood glucose levels are, how well they are controlled and other factors in the pregnancy.

This is why diagnosis and appropriate management matter.

Does Gestational Diabetes Affect the Baby?

Gestational diabetes can affect the baby's growth and health around the time of birth, particularly when blood glucose levels are not well controlled.

However, having gestational diabetes does not automatically mean that something will go wrong.

With appropriate monitoring and treatment, many women with GDM have healthy pregnancies and healthy babies.

Your obstetrician may recommend additional monitoring depending on your blood glucose levels and overall pregnancy.

Can Gestational Diabetes Go Away After Delivery?

In many cases, blood glucose levels return to normal after pregnancy.

However, having gestational diabetes is associated with an increased future risk of developing type 2 diabetes for the mother. Children born after pregnancies affected by gestational diabetes may also have a higher long-term risk of metabolic problems.

This makes postpartum follow-up important, even after blood sugar returns to normal.

Your doctor may recommend blood glucose testing after delivery and periodic monitoring later.

Can You Prevent Gestational Diabetes?

There is no guaranteed way to prevent gestational diabetes.

However, entering pregnancy at a healthy weight when possible, eating a balanced diet, staying physically active, and managing existing health conditions can support overall metabolic health.

Importantly, gestational diabetes is not a sign that you did something wrong.

Some women develop it despite having a healthy diet and active lifestyle.

The focus should be on early detection, appropriate care and healthy habits rather than guilt.

Frequently Asked Questions

Can gestational diabetes happen if I am not overweight?

Yes. Gestational diabetes can occur in women of any body size. Weight is only one of several factors that may influence risk.

Does eating sweets cause gestational diabetes?

Not directly. Gestational diabetes is primarily related to the body's response to insulin and the metabolic changes of pregnancy. Eating a lot of sugary foods is not, by itself, a simple explanation for why someone develops GDM.

Can gestational diabetes have no symptoms?

Yes. Many women have no noticeable symptoms, which is why routine prenatal screening is important.

At what week is gestational diabetes tested?

The usual testing window is 24 to 28 weeks of pregnancy. Some women may need earlier assessment depending on their medical history or risk factors.

Can gestational diabetes affect the baby?

Uncontrolled high blood glucose during pregnancy can increase the risk of complications affecting the baby and the delivery. Appropriate monitoring and treatment can help reduce these risks.

Does gestational diabetes mean I will have diabetes after pregnancy?

Not necessarily. Blood glucose often returns to normal after delivery. However, women who have had gestational diabetes have a higher future risk of developing type 2 diabetes and should follow their doctor's recommendations for postpartum testing and ongoing health monitoring.

Can I have a normal delivery with gestational diabetes?

Yes. Many women with gestational diabetes have vaginal deliveries. The mode and timing of delivery depend on factors such as blood glucose control, baby's growth, gestational age and other pregnancy considerations.

Conclusion

Gestational diabetes is a common pregnancy-related health condition that deserves attention, but it does not mean that you cannot have a healthy pregnancy.

Because it often causes few or no noticeable symptoms, testing matters even when you feel completely well. The usual window for testing is 24–28 weeks, although your doctor may recommend earlier assessment depending on your health history and risk factors.

If you are diagnosed with gestational diabetes, remember that you are not alone and that the condition can be managed. Working closely with your obstetrician and following your personalised plan for nutrition, activity, blood glucose monitoring and medication when needed can help support a healthier pregnancy.

Medical Disclaimer: This article is intended for general educational purposes only and should not be considered a substitute for personalised medical advice, diagnosis or treatment. Screening practices and diagnostic criteria may vary by healthcare setting. If you are pregnant or concerned about your blood glucose levels, speak with your obstetrician or qualified healthcare professional.