Introduction

Being told that you have gestational diabetes can be worrying, particularly if your blood sugar was normal before pregnancy.

Gestational diabetes mellitus, often shortened to GDM, is a form of diabetes that develops during pregnancy. It occurs when blood glucose rises above the healthy range because the body cannot produce or use enough insulin to meet the changing demands of pregnancy.

It is important to remember that developing GDM does not mean that you have failed at pregnancy or that you have simply eaten too much sugar.

Pregnancy naturally changes the way insulin works in the body. For some women, the pancreas cannot produce enough additional insulin to compensate, causing glucose levels to rise.

With appropriate monitoring and treatment, many women with gestational diabetes go on to have healthy pregnancies and babies.

Insulin is a hormone that helps glucose move from the bloodstream into cells, where it can be used for energy.

During pregnancy, hormonal changes can make the body less sensitive to insulin. This is known as insulin resistance.

Normally, the pancreas responds by producing more insulin. Gestational diabetes develops when this additional insulin is not enough to keep blood glucose within the recommended range.

GDM commonly develops later in pregnancy as hormonal and metabolic demands increase.

Unlike type 1 or type 2 diabetes that was already present before pregnancy, gestational diabetes is first recognised during pregnancy.

As pregnancy progresses, the placenta produces hormones that help support the developing baby.

Some of these hormonal changes also make insulin less effective. This means the mother's body needs to produce more insulin to keep blood glucose under control.

When the pancreas cannot keep up with this increased demand, blood glucose levels rise.

This helps explain why GDM can appear in someone who had normal glucose levels before pregnancy.

Gestational diabetes is therefore not something that can always be predicted simply from how healthy someone appears.

Gestational diabetes can occur in any pregnancy, although some women have a higher risk than others.

Risk may be higher in women who have previously had gestational diabetes, are overweight before pregnancy, have a strong family history of diabetes or have previously delivered a large baby.

Polycystic ovary syndrome and other metabolic risk factors may also increase the likelihood of glucose problems.

However, having no obvious risk factors does not guarantee that GDM will not develop.

This is one reason routine pregnancy screening is important rather than testing only women who appear to be at high risk.

In Singapore, pregnant women are generally offered screening for gestational diabetes using an oral glucose tolerance test, or OGTT, between 24 and 28 weeks of pregnancy.

The test measures how the body handles glucose.

You will usually be asked to fast before the test. A blood sample is taken, followed by a glucose drink, with additional blood samples taken afterwards according to the testing protocol.

The results allow the healthcare team to determine whether blood glucose exceeds the recommended pregnancy thresholds.

Some women may require testing earlier in pregnancy when their medical history or other factors suggest a higher risk.

Managing gestational diabetes matters because persistently high blood glucose can affect both mother and baby.

Extra glucose in the mother's bloodstream can cross the placenta. The baby's body may respond by producing more insulin, which can contribute to increased growth.

A larger baby can make delivery more complicated and may increase the chance that additional obstetric intervention is needed.

Poorly controlled GDM is also associated with pregnancy complications including high blood pressure and preterm delivery.

After birth, babies exposed to high maternal glucose levels may be at risk of low blood sugar and may require appropriate monitoring.

These risks do not mean that complications will definitely happen. Effective management of blood glucose is intended to reduce these risks.

Management usually combines blood glucose monitoring, healthy eating, appropriate physical activity and regular antenatal follow-up.

Some women can maintain glucose within their recommended targets using lifestyle measures alone.

Others may require medication, including insulin, when lifestyle changes are not sufficient to achieve appropriate glucose levels.

If you are asked to monitor your blood glucose at home, your healthcare team will explain how and when to test and what target range is appropriate for you.

Keep a record of the results if requested. Patterns across several days can help the healthcare team determine whether your current management plan is working.

Do not change insulin doses or other treatment without following the instructions from your maternity or diabetes care team.

A GDM-friendly eating plan is not about removing all carbohydrates or eating as little as possible.

Carbohydrates are an important source of energy, but the amount, type and timing can influence blood glucose.

KK Women's and Children's Hospital advises women with GDM to pay attention to what and how much they eat in order to manage glucose while still meeting pregnancy nutrition needs.

Meals can include vegetables, appropriate portions of carbohydrate foods, protein-rich foods and other nutrient-dense choices.

Wholegrain or higher-fibre carbohydrate choices may help provide more fibre than highly refined alternatives. Sugary drinks and foods high in added sugars can raise glucose quickly and are generally worth limiting.

Spacing carbohydrate intake across meals and snacks may also help some women avoid very large glucose rises at one time.

The exact eating plan should be individualised. Pregnancy is not the time for crash dieting or highly restrictive eating patterns.

Can Exercise Help?

Physical activity can support glucose management because working muscles use glucose for energy and activity can improve insulin sensitivity.

Walking is one accessible option for many pregnant women, and some women may find a gentle walk after meals practical.

Other activities may also be appropriate depending on your pregnancy, previous fitness level and medical circumstances.

Pregnancy exercise should always take individual health and obstetric factors into account. If you have been advised to restrict activity or have pregnancy complications, follow the recommendations of your healthcare team.

Does Having GDM Mean You Will Need a Caesarean?

No. A diagnosis of gestational diabetes does not automatically mean that you will need a caesarean delivery.

The delivery plan depends on many factors, including glucose control, the baby's growth, the progress of pregnancy and other obstetric considerations.

Your maternity team will monitor these factors and discuss the safest delivery plan with you.

Does GDM Mean Your Baby Will Have Diabetes?

Gestational diabetes does not mean that your baby is born with diabetes simply because the mother's glucose was elevated during pregnancy.

However, GDM is one factor associated with longer-term metabolic risks for both mother and child.

The immediate priority during pregnancy is to manage maternal glucose appropriately and monitor the baby's growth and well-being.

For many women, blood glucose returns toward the normal range after the baby is born because the pregnancy-related hormonal changes that contributed to insulin resistance are no longer present.

However, having gestational diabetes increases a woman's future risk of developing type 2 diabetes.

This means follow-up remains important even if glucose returns to normal after delivery.

Your healthcare team may recommend a glucose test after pregnancy to check whether your glucose regulation has returned to an appropriate range.

Longer-term healthy eating, regular physical activity and maintaining an appropriate body weight can support overall metabolic health.

Make sure future healthcare professionals know that you previously had gestational diabetes because this history remains relevant to your diabetes risk.

Managing GDM Without Blame

Pregnancy already comes with a long list of things mothers are told they should and should not do. A diagnosis of GDM can sometimes create unnecessary feelings of guilt.

Gestational diabetes develops because pregnancy changes insulin requirements and some bodies are unable to compensate sufficiently.

Healthy lifestyle choices matter for management, but the diagnosis itself is not proof that someone ate badly or failed to look after herself.

The most useful response is to focus on what can be controlled now: follow-up appointments, glucose monitoring, balanced meals, appropriate physical activity and treatment when required.