Overview
Gestational diabetes is a form of high blood sugar that develops during pregnancy in women who did not have diabetes beforehand. It usually appears in the second half of pregnancy, when hormonal changes make the body more resistant to insulin.
Disease Summary
- Category
- Non-Communicable Disease
- Cause
- Insulin resistance during pregnancy that outpaces the body's insulin supply
- Transmission
- Not applicable; gestational diabetes is a pregnancy-specific metabolic condition and cannot be spread between people
- Body System
- Endocrine System
- Preventable
- Yes
- Curable
- Yes
Symptoms
Common Symptoms
Gestational diabetes often causes no symptoms at all. When symptoms do occur, they tend to be mild and easy to mistake for ordinary pregnancy changes.
Increased Thirst
Feeling thirstier than usual is one of the more commonly reported symptoms.
Frequent Urination
Needing to urinate more often than expected for the stage of pregnancy.
Fatigue
Feeling unusually tired, though this can overlap with normal pregnancy fatigue.
Blurred Vision
Temporary changes in vision can occur when blood sugar levels are elevated.
Danger Signs
Seek urgent medical attention immediately if any of the following symptoms develop.
Very High Blood Sugar Readings
Readings significantly above the target range require prompt guidance from a healthcare provider.
Reduced Fetal Movement
A noticeable decrease in the baby’s movements should be reported immediately.
Severe Headache with Vision Changes
May signal a related complication such as preeclampsia and needs urgent evaluation.
Signs of Very Low Blood Sugar
Shakiness, confusion, or fainting can occur with insulin treatment and require immediate attention.
Diagnosis
Clinical Assessment
Diagnosis is guided by routine prenatal screening rather than by symptoms, since most women feel well.
Glucose Screening
Most women are screened between 24 and 28 weeks of pregnancy, with earlier testing offered to those at higher risk.
Oral Glucose Tolerance Test (OGTT)
A confirmatory test measuring how the body processes a sugary drink is used to establish the diagnosis.
Laboratory Tests
Oral Glucose Tolerance Test (OGTT)
The primary diagnostic test, measuring blood sugar before and at set intervals after drinking a glucose solution.
Fasting Blood Glucose
Measures blood sugar after a period without eating and can be used as part of screening or diagnosis.
Glucose Challenge Test
A one-step screening test used in some settings to identify women who need the full OGTT.
Haemoglobin A1c
Reflects average blood sugar over recent months and can help identify pre-existing diabetes at the first prenatal visit.
Treatment
Nutrition and Physical Activity
A structured meal plan and regular physical activity are the first-line treatment and manage blood sugar for most women.
Insulin Therapy
Insulin is added when diet and exercise are not enough to keep blood sugar within target range, and is considered safe in pregnancy.
Prevention
Maintain a healthy weight before pregnancy
Entering pregnancy at a healthy weight lowers the likelihood of developing gestational diabetes.
Stay physically active
Regular exercise before and during pregnancy, as approved by a healthcare provider, improves insulin sensitivity.
Eat a balanced diet
Choosing whole grains, vegetables, and lean protein while limiting refined sugar supports healthy blood sugar levels.
Attend recommended screening
Completing glucose screening at the recommended time in pregnancy allows early detection and treatment.
Risk Factors
High Risk
These factors substantially increase the likelihood of developing gestational diabetes.
- Overweight or obesity before pregnancy
- Gestational diabetes in a previous pregnancy
- Polycystic ovary syndrome (PCOS)
- Family history of type 2 diabetes
Increased Risk
These factors are associated with a moderately higher risk of gestational diabetes.
- Maternal age over 25
- Previous delivery of a large baby
- History of unexplained stillbirth
- Certain ethnic backgrounds with higher population risk
Additional Contributing Factors
Other factors linked with an increased likelihood of gestational diabetes.
- Multiple pregnancy (twins or more)
- High blood pressure before pregnancy
- Rapid weight gain in early pregnancy
Complications
Fetal Macrosomia
Babies exposed to high blood sugar in the womb can grow larger than average, increasing the risk of a difficult delivery.
Preeclampsia
Gestational diabetes increases the risk of developing high blood pressure and organ dysfunction later in pregnancy.
Neonatal Hypoglycaemia
Babies can experience low blood sugar shortly after birth as their bodies adjust to no longer receiving extra glucose from the mother.
When to Seek Medical Care
Persistently High Blood Sugar Readings
Readings that remain above target despite following the treatment plan should be reported promptly.
Symptoms of Low Blood Sugar
Shakiness, sweating, confusion, or fainting while on insulin or other medication require immediate attention.
Reduced Fetal Movement
A noticeable decrease in the baby’s movements should be assessed by a healthcare provider right away.
Signs of Preeclampsia
Severe headache, vision changes, or upper abdominal pain need urgent evaluation.
Prognosis
Good with Consistent Management
Most women with gestational diabetes have healthy pregnancies and deliveries when blood sugar is kept within target range.
Usually Resolves After Delivery
Blood sugar typically returns to normal soon after the baby is born, though it should still be checked postpartum.
Increased Future Risk
Women who have had gestational diabetes have a higher lifetime risk of developing type 2 diabetes and may develop gestational diabetes again in future pregnancies.
Differential Diagnosis
Pre-existing Type 2 Diabetes
High blood sugar detected early in pregnancy, particularly at the first prenatal visit, may reflect diabetes that existed before pregnancy rather than gestational diabetes.
Type 1 Diabetes
An autoimmune condition involving little or no insulin production, which can occasionally be recognised for the first time during pregnancy.
Impaired Glucose Tolerance
Blood sugar levels that are higher than normal but do not meet the threshold for a gestational diabetes diagnosis may still warrant closer monitoring.
References
Centers for Disease Control and Prevention (CDC)
Guidance on the causes, symptoms, screening, and management of gestational diabetes.
Centers for Disease Control and Prevention (CDC)
Information on diabetes during pregnancy and reducing future risk after a gestational diabetes diagnosis.
World Health Organization (WHO) Diagnostic Criteria
Peer-reviewed reference describing the WHO 2013 diagnostic criteria for gestational diabetes mellitus.
Frequently Asked Questions
Can gestational diabetes be cured?
Blood sugar usually returns to normal after delivery, so gestational diabetes typically resolves on its own once the pregnancy ends.
Will I need insulin if I have gestational diabetes?
Not always. Many women manage it with diet and exercise alone, though some need insulin or other medication if targets are not met.
Can gestational diabetes be prevented?
Maintaining a healthy weight, staying active, and eating a balanced diet can lower the risk, though not every case can be prevented.
Does gestational diabetes affect future pregnancies?
Yes. Women who have had gestational diabetes are more likely to develop it again in later pregnancies and have a higher lifetime risk of type 2 diabetes.