Gestational Diabetes: Symptoms, Screening Tests, Risks and Pregnancy Care

Gestational diabetes is a type of high blood sugar first recognised during pregnancy. It can develop even in women who have never had diabetes and feel completely healthy. This is why routine blood glucose screening is an important part of antenatal care.

When blood sugar remains higher than recommended during pregnancy, it can increase the risk of complications for both the mother and baby. The good news is that gestational diabetes can often be managed with appropriate nutrition, physical activity, blood glucose monitoring and medication when required.

Understanding the screening process, possible warning signs and treatment options can help you take the right steps during pregnancy.

What Is Gestational Diabetes?

Gestational diabetes mellitus (GDM) is a condition in which elevated blood glucose is first identified during pregnancy and does not meet the criteria for overt diabetes. It can occur in women who have never previously been diagnosed with diabetes. 

During pregnancy, hormones produced by the placenta can make the body's cells less responsive to insulin. Insulin is the hormone that helps glucose move from the bloodstream into cells for energy.

The pancreas normally produces more insulin to compensate for this increased resistance. If the body cannot produce enough insulin to meet the increased demand, blood glucose levels rise.

Gestational diabetes is different from diabetes that was already present before pregnancy. However, testing early in pregnancy may identify previously undiagnosed diabetes, which needs a different assessment and management plan.

What Are the Symptoms of Gestational Diabetes?

Most women with gestational diabetes do not notice clear symptoms. The condition is often identified during routine pregnancy screening rather than because a woman feels unwell.

Some women may experience:

Increased thirst.

Passing urine more frequently than expected.

Unusual tiredness.

Dry mouth.

Blurred vision.

These symptoms can also occur during an otherwise normal pregnancy or with other medical conditions. They cannot confirm gestational diabetes.

Do not wait for symptoms before getting screened. A woman can have elevated blood glucose without feeling any different.

Who Has a Higher Risk of Gestational Diabetes?

Gestational diabetes can develop in any pregnancy, but certain factors may increase the likelihood.

Risk factors include:

Previous gestational diabetes.

A previous baby with a high birth weight.

Overweight or obesity before pregnancy.

A parent or sibling with type 2 diabetes.

Polycystic ovary syndrome (PCOS).

Previously identified prediabetes or elevated blood glucose.

Older maternal age, particularly 35 years or above. 

Having one or more risk factors does not mean that you will definitely develop gestational diabetes. Similarly, women without known risk factors can still develop it.

When Is Gestational Diabetes Screening Done?

FOGSI's 2024 recommendations advise screening for gestational diabetes during the first antenatal visit, preferably as early as possible in pregnancy. If the initial result is negative, repeat testing is recommended during the second trimester, generally around 24–28 weeks. The detailed FOGSI guidance on hyperglycaemia in pregnancy specifies 24–26 weeks. In selected women at higher risk, another assessment at 32–34 weeks may be considered.

This timing matters because insulin resistance increases as pregnancy progresses. A woman whose early test is normal may develop gestational diabetes later.

If you start antenatal care after 28 weeks, your doctor will decide the appropriate screening approach based on your gestational age and clinical circumstances.

Women with significant risk factors may need early assessment to identify previously undiagnosed diabetes. Women who already have diabetes before pregnancy require a separate pre-existing diabetes management plan rather than routine gestational diabetes screening.

How Is Gestational Diabetes Diagnosed in India?

The Diabetes in Pregnancy Study Group of India (DIPSI) method is widely used in Indian public health and obstetric practice.

Under this approach, the woman is given a 75-gram oral glucose load, regardless of whether she has eaten recently. A blood glucose measurement is taken two hours later.

Under the DIPSI diagnostic approach, a two-hour plasma glucose value of 140 mg/dL or higher is used to diagnose gestational diabetes.

The exact testing protocol and interpretation should follow the clinical guideline and laboratory method used by the treating facility.

Why might different hospitals use different glucose tests?

You may read about a fasting oral glucose tolerance test, a one-hour glucose challenge test or a multi-sample glucose test.

These are different screening or diagnostic approaches used in different healthcare systems and clinical protocols. For example, some international guidelines use a two-step screening pathway, while Indian recommendations commonly refer to DIPSI.

Do not compare results from different tests without checking the glucose load, timing of the blood sample and diagnostic criteria. Your obstetrician should explain which test is being used and what your result means.

What Happens If Your Gestational Diabetes Test Is Abnormal?

The next step depends on which glucose testing method was used and the result obtained. Under the DIPSI approach, a two-hour plasma glucose value of 140 mg/dL or higher after a 75-gram glucose load meets the diagnostic threshold for gestational diabetes.

If another screening method has been used, an abnormal screening result may require additional diagnostic testing according to that protocol. Your doctor will also assess whether elevated glucose detected early in pregnancy could represent previously undiagnosed diabetes.

Once gestational diabetes is diagnosed, the care plan usually includes blood glucose monitoring, individualised nutritional advice, suitable physical activity and follow-up appointments.

The purpose is to keep blood glucose within the target range recommended by your treating team and reduce the chance of complications.

How Can Gestational Diabetes Affect the Mother and Baby?

When blood glucose remains poorly controlled, gestational diabetes can increase the risk of several pregnancy complications.

Possible effects on the baby

Higher maternal glucose levels can lead to increased glucose transfer to the baby. The baby's pancreas responds by producing more insulin, which can contribute to excessive growth.

Possible complications include:

A larger-than-expected baby, also called fetal macrosomia.

Increased likelihood of difficult delivery, including shoulder dystocia.

Low blood glucose in the newborn after birth.

Increased need for newborn monitoring or additional care.

Higher long-term risk of obesity and glucose-related health problems.

Not every baby exposed to gestational diabetes will develop these complications. Good glucose control and appropriate antenatal monitoring help reduce risks.

Possible effects on the mother

Gestational diabetes can increase the likelihood of high blood pressure and pre-eclampsia. It may also affect delivery planning, particularly when the baby is estimated to be larger than expected.

Women who have had gestational diabetes also have a higher risk of developing type 2 diabetes later in life. Follow-up after delivery is therefore important, even when blood glucose returns to normal after pregnancy.

How Is Gestational Diabetes Managed During Pregnancy?

Treatment is individualised. Many women can initially manage their blood glucose through nutrition changes and suitable physical activity. Others need medication to achieve their glucose targets.

1. Follow an individualised meal plan

The aim is not to stop eating carbohydrates or follow an extreme diet. Instead, the focus is on appropriate portions, balanced meals and choosing carbohydrate sources that support more stable blood glucose levels.

Your meal plan may include:

Whole grains and suitable portions of cereals.

Pulses, beans and other protein sources.

Vegetables and fibre-rich foods.

Appropriate portions of fruit.

Milk, curd or other suitable calcium-rich foods.

Healthy sources of fat.

Try to avoid sugary drinks and frequent intake of foods with large amounts of added sugar. The timing and distribution of meals should be discussed with your dietitian or treating clinician.

Do not skip meals or follow a restrictive weight-loss diet during pregnancy.

2. Include suitable physical activity

If your obstetrician has not advised activity restrictions, regular moderate activity can support blood glucose control.

Walking after meals may be suitable for many pregnant women. The type, duration and intensity of exercise should be adjusted according to your pregnancy, fitness level and any medical complications.

Stop exercising and seek medical advice if you experience concerning symptoms such as vaginal bleeding, dizziness, chest pain, breathlessness before exertion or painful contractions.

3. Monitor blood glucose levels

Your doctor may ask you to check blood glucose at specific times, such as fasting and after meals.

The target values and frequency of testing depend on the clinical protocol and your individual condition. Record your readings and bring them to follow-up appointments.

A glucose record helps your doctor understand whether meal changes and physical activity are working or whether treatment needs adjustment.

Commonly used blood glucose targets during gestational diabetes management include:

Fasting or pre-meal blood glucose: below 95 mg/dL.

One-hour post-meal blood glucose: below 140 mg/dL.

Two-hour post-meal blood glucose: below 120 mg/dL.

Your obstetrician may advise monitoring at one hour or two hours after meals, depending on your treatment plan. These are treatment targets, not the diagnostic thresholds used for the DIPSI test.

This distinction is particularly important because patients often confuse screening values with daily monitoring targets.

4. Take medication if prescribed

If blood glucose levels remain above the recommended targets despite appropriate nutrition management and physical activity, medication may be needed to manage gestational diabetes.

Insulin is the drug of choice when medication is required during pregnancy. It does not cross the placenta and is commonly used to help maintain blood glucose within the recommended range.

In selected circumstances, your doctor may consider metformin, particularly if you decline insulin or cannot use it safely or afford it. Before starting metformin, your doctor should discuss its potential benefits, limitations and the available safety evidence. Some women taking metformin may still require insulin to achieve their blood glucose targets.

Do not start, stop or change insulin or oral medication on your own. Your treatment plan should be individualised and supervised by your obstetrician, with input from a diabetes specialist when needed.

Does Gestational Diabetes Always Mean a Caesarean Delivery?

Decisions about birth planning are made according to maternal health, fetal growth and the progress of pregnancy. These considerations form part of individualised pregnancy and delivery care.

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

The mode and timing of delivery depend on blood glucose control, estimated fetal growth, maternal health, gestational age, previous obstetric history and other pregnancy-related factors.

Some women with gestational diabetes can have a vaginal birth. Others may need induction of labour or a caesarean delivery for specific medical reasons.

Your obstetrician will discuss the benefits and risks of the available options based on your pregnancy.

What Follow-Up Is Needed After Delivery?

Gestational diabetes often improves after the placenta is delivered, but the risk of future diabetes remains higher than in women who have not had the condition.

Postpartum blood glucose testing is important to check whether glucose levels have returned to the expected range or whether diabetes or prediabetes is present.

The timing and type of postpartum test should follow your doctor's advice and the applicable clinical guideline. Long-term follow-up, healthy eating, physical activity and appropriate weight management can help reduce future metabolic risk.

Women planning another pregnancy may also benefit from discussing their health and diabetes risk during pre-conception counselling.

Frequently Asked Questions About Gestational Diabetes

1. Can gestational diabetes develop if my previous pregnancy was normal?

Yes. Gestational diabetes can develop in a later pregnancy even if your previous pregnancy had normal blood glucose levels. Each pregnancy needs its own assessment and recommended screening.

2. Can I have gestational diabetes if I am not overweight?

Yes. Gestational diabetes can occur in women of any body weight. Weight is one risk factor, but it is not the only one. Routine screening is important even if you do not have recognised risk factors.

3. Will gestational diabetes go away after childbirth?

Blood glucose often improves after delivery because the hormonal changes of pregnancy begin to resolve. However, some women continue to have elevated blood glucose or are later diagnosed with type 2 diabetes. Postpartum testing is important to check this.

4. Can I breastfeed if I had gestational diabetes?

Yes. Having had gestational diabetes does not prevent you from breastfeeding. Breastfeeding is generally encouraged when medically appropriate and can support the health of both mother and baby.

5. Should I check my blood sugar at home if my screening test is normal?

Not automatically. Home glucose monitoring is usually advised when there is a clinical reason, such as a diagnosis of gestational diabetes or another glucose-related concern. Follow your obstetrician's instructions rather than testing unnecessarily.

6. Can gestational diabetes affect my chances of developing diabetes later?

Yes. Women who have had gestational diabetes have a higher future risk of type 2 diabetes. Regular follow-up and periodic glucose testing are important even when blood sugar returns to normal after delivery.

Gestational Diabetes Care in Noida 

Important Information for Women with Gestational Diabetes

Gestational diabetes requires appropriate screening, interpretation of blood glucose results and follow-up throughout pregnancy.

Women who receive an abnormal glucose result should discuss the findings, monitoring schedule and treatment options with their obstetric care team. Diet, physical activity and medication recommendations should be based on individual clinical assessment.