X
Table of contents

Gestational diabetes

Feel like sharing?

What is gestational diabetes?

Gestational diabetes is a form of diabetes that occurs during pregnancy. It is marked by high blood sugar (glucose) levels in pregnant women who ordinarily do not have diabetes. It commonly occurs between the 24th and 28th week of pregnancy, and in some cases even earlier. Gestational diabetes is a type of diabetes that can develop during pregnancy in women who don't already have diabetes. Every year, 2% to 10% of pregnancies in the United States are affected by gestational diabetes. Managing gestational diabetes will help make sure you have a healthy pregnancy and a healthy baby.

This form of diabetes is caused by normal pregnancy hormones, which are released by the placenta. These hormones reduce the normal function of the mother's insulin. Insulin is an important chemical released by the pancreas to regulate blood sugar levels. In the presence of pregnancy hormones, normal levels of insulin are no longer able to control blood sugar levels, which is called insulin resistance. Normally, the mother's body produces up to two to three times more insulin than usual, to compensate for the insulin resistance. However, in gestational diabetes not enough insulin is produced, resulting in high blood sugar levels that may affect the pregnancy and the unborn baby's health.

The condition commonly settles soon after birth, as the pregnancy hormones disappear. However, it may increase the risk of developing diabetes in the future.

Causes

Glucose is an essential energy source for the body's cells. When food containing carbohydrates is eaten, it is broken down into glucose that travels around the body in the blood, to be absorbed by cells to use as an energy source. Insulin, a hormone produced by the pancreas, functions to help cells take in the glucose from the blood, thus regulating the blood glucose levels.

During pregnancy, hormones (such as growth factor, prolactin, progesterone and cortisol) are produced by the placenta to help the baby grow and develop. These same hormones can reduce the actions of the mother's insulin, leading to insulin resistance.

If insufficient insulin is produced to compensate for the insulin resistance, blood glucose levels will remain abnormally high, as seen in gestational diabetes. The consequence of high blood glucose levels during pregnancy can be:

To the unborn baby:

To the mother:

The process of gestational diabetes. 

Risk factors

Factors that can increase the risk of developing gestational diabetes include:

  • Being more than 30 years of age;
  • Having gestational diabetes in a previous pregnancy;
  • Having polycystic ovary syndrome (PCOS);
  • Having had a baby in a previous pregnancy whose weight at birth was more than 10 pounds (4.5 kilograms);
  • Being overweight or obese;
  • Having a family history of type 2 diabetes or gestational diabetes, and;
  • Taking steroids or antipsychotic medications.

Women from some cultural and ethnic groups are also at a higher risk, including:

  • People of Indian descent;
  • People of Vietnamese and Chinese descent;
  • People of Middle Eastern descent, and;
  • People of Polynesian or Melanesian background.

Signs and symptoms

Women with gestational diabetes often have no noticeable symptoms. However, they can include:

Methods for diagnosis

Gestational diabetes is assessed using two different laboratory tests, which both test for insulin resistance in the mother.

Glucose challenge test (GCT)

In this test, no fasting or change to your usual diet is required before the test is performed. You will have a blood test to measure the level of glucose in the blood. This will give a baseline-level blood glucose. You will then be given a drink containing glucose (either 50 or 75 grams of glucose) and an hour later another blood sample will be taken to measure the difference in your blood glucose level. Test results greater than 7.8 (for 50 grams of glucose) or 8.0 mmol/L (for 75 grams of glucose) indicate a need for further testing. This test does not diagnose gestational diabetes, but indicates if you are at increased risk and need further testing.

It is important to remember that many women do not experience any noticeable symptoms with gestational diabetes, therefore it is recommended that all pregnant women be screened by means of a glucose challenge test when they are between 26-28 weeks' gestation.

Oral glucose tolerance test (OGTT)

This test is performed if the glucose challenge test indicates possible gestational diabetes. Prior to the test, you will need to fast overnight. You will have a blood test to measure your blood glucose level in the morning. You will then be given a drink containing 75 grams of glucose and after one and two hours, further blood tests are taken.

Gestational diabetes is diagnosed if:

Types of treatment

If you are diagnosed with gestational diabetes, you will usually receive additional care from doctors, specialists and other healthcare professionals during your pregnancy. The key to treatment of gestational diabetes is controlling blood glucose levels. This can be achieved using different treatments:

Lifestyle changes

Most women with gestational diabetes can control their condition using lifestyle measures such as eating a healthy diet and being physically active.

Healthy diet

Eating a well-balanced diet can help with maintaining healthy blood glucose levels. A diet that is low in fat, with plenty of fruits, vegetables and whole grains is recommended. If you need help planning your meals, a dietitian can provide guidance.

A well-balanced diet can help to provide healthy glucose levels. 

Physical activity

Regular physical activity is an important part of controlling blood glucose. However, it is important to talk to your doctor about what activities are suitable and any precautions you may need to take.

Weight management

Maintaining a healthy weight can help you to manage gestational diabetes and stay healthy during pregnancy. As every woman's situation is different, your doctor can advise you on what weight goals may be suitable for you.

Self-testing

Monitoring your own blood glucose levels at home is important to assess if the treatments are working. This is done using a blood glucose machine, which analyses your glucose level from a blood sample obtained by a finger prick. You will be taught how to perform self-testing by your doctor or a diabetic nurse.

The frequency of testing will depend on the fluctuation of your blood glucose levels and the type of treatment you receive, which your doctor can advise you on.

Medication

Some women with gestational diabetes require treatment with insulin to keep their blood glucose levels under control. Insulin needs to be injected and cannot be taken as a tablet.

There are many different types of insulin that have different periods of activity including:

Potential complications

Effects on the baby

Babies of mothers who have gestational diabetes tend to be larger and weigh more at birth. This increases the risk of birth injury.

They may experience more episodes of low blood glucose levels (hypoglycemia) in the first few days.

If gestational diabetes is not treated, there is a slightly increased risk of the baby dying.

Effects on the mother

Due to a larger baby and the increased risk of complications with delivery, the mother has an increased likelihood of needing a caesarean section.

There is an increased risk of low blood glucose levels (hypoglycemia). It can happen to people taking medication for diabetes, particularly if they delay or miss a meal, drink alcohol or are more physically active than usual.

If blood sugar levels fall too low, symptoms can include:

Severe hypoglycemia is a serious condition and can cause people to lose consciousness. Monitoring blood glucose levels and taking early steps to bring them back to normal can help to prevent hypoglycemia.

Increased risk of type 2 diabetes

While blood glucose tends to return to normal levels after birth, women who have had gestational diabetes have a greater risk of developing type 2 diabetes later in life, often within 5-10 years.

Women who have had gestational diabetes are recommended to have a glucose tolerance test 6-12 weeks after giving birth and then a fasting blood glucose test every three years after that. A fasting blood glucose test is a blood sample taken after an overnight fast.

Prognosis

With appropriate lifestyle management and treatment, most women with gestational diabetes can manage blood glucose levels well and avoid serious health consequences for themselves and their babies.

Prevention

Gestational diabetes cannot always be prevented, but taking measures before pregnancy to achieve a healthy weight can help to reduce your risk.

Prenatal care can help to diagnose gestational diabetes early and identify any other health problems that may occur during pregnancy.

References

  1. Diabetes in pregnancy: its impact on Australian women and their babies. Australian Institute of Health and Welfare. Accessed 24 November 2014 from link here
  2. Diabetes and Antipsychotic Drugs - Australian Prescriber. Accessed July 24 2014. link here
  3. Diabetes - Gestational | Better Health Channel. Accessed July 23 2014. link here
  4. Diabetes in Australia - Diabetes Australia. Accessed July 23 2014. link here
  5. Diabetes in Pregnancy: Its Impact on Australian Women and Their Babies (full Publication; 23/11/2010 Edition) (AIHW) - dip2010-Aihw.pdf. Accessed November 24 2014. link here
  6. Gestational Diabetes - Diabetes Australia. Accessed July 24 2014. link here
  7. Gestational Diabetes - National Library of Medicine - PubMed Health. Accessed July 23 2014. link here
  8. Hypoglycaemia - Diabetes Australia. Accessed July 22 2014. link here
  9. Insulin - Diabetes Australia. Accessed July 22 2014. link here

11 Most frequently asked questions (FAQs)

What is gestational diabetes?
Gestational diabetes is a form of diabetes that occurs during pregnancy. It is marked by high blood sugar (glucose) levels in pregnant women who ordinarily don't have diabetes. It commonly occurs between the 24th and 28th week of pregnancy, and in some cases even earlier.
What are the symptoms of gestational diabetes?
Women with gestational diabetes often have no noticeable symptoms. When they do appear, symptoms can include: increased thirst; increased hunger; needing to urinate more often; tiredness and fatigue; unexpected weight loss; infections of the bladder, skin and vagina; Nausea and vomiting, and; blurred vision.
What causes gestational diabetes?
Insulin is an important hormone that controls blood glucose levels. Normal pregnancy hormones that are produced by the placenta reduce the actions of insulin in the mother's body, an effect known as insulin resistance. If not enough insulin is produced to compensate for the insulin resistance, blood glucose levels will remain abnormally high, as seen in gestational diabetes.
Who gets gestational diabetes?
Approximately 3-8% of pregnant women can develop gestational diabetes, often at around 24 to 28 weeks' gestation. Factors that can increase the risk of developing gestational diabetes include: being over 30 years of age; having gestational diabetes in a previous pregnancy; having polycystic ovary syndrome (PCOS); having had a baby in a previous pregnancy whose weight at birth was more than 4.5 kilograms; being overweight or obese; having a family history of type 2 diabetes or gestational diabetes, and; taking steroids or anti-psychotic medications. Women from some cultural and ethnic groups are also at a higher risk, including: Aboriginal and Torres Strait Islanders; people of Indian descent; people of Vietnamese and Chinese descent; people of Middle Eastern descent, and; people of Polynesian or Melanesian background.
How is gestational diabetes diagnosed?
Gestational diabetes is diagnosed using the oral glucose tolerance test (OGTT). This test involves taking a blood sample after fasting overnight, then having a drink containing 75 grams of glucose, followed by further blood samples at one and two hours after the drink. The blood samples test for high blood glucose levels. If the blood glucose levels are above 5.5 mmol/L after fasting, and/or above 8.0 mmol/L two hours after the glucose drink, then this is consistent with gestational diabetes.
How is gestational diabetes treated?
Most women with gestational diabetes can control their condition using lifestyle measures such as eating a healthy diet and being physically active. Some women do require treatment with insulin to keep their blood glucose levels under control. Insulin needs to be injected and cannot be taken as a tablet.
Will gestational diabetes clear on its own?
Gestational diabetes needs to be managed during pregnancy to avoid complications for the mother and baby. Blood glucose tends to return to normal levels after birth.
Can gestational diabetes be prevented?
Gestational diabetes cannot always be prevented, but taking measures before pregnancy to achieve a healthy weight, good nutritional intake and exercise can help to reduce your risk. Prenatal care can help to diagnose gestational diabetes early and identify any other health problems that may occur during pregnancy.
Will gestational diabetes keep coming back?
Women who have had gestational diabetes in one pregnancy are more likely to develop it in subsequent pregnancies. They also have a higher risk of developing type 2 diabetes later in life.
Is gestational diabetes serious?
While gestational diabetes can be readily managed with the combination of lifestyle measures such as a healthy diet, regular and appropriate physical activity and insulin (when required), if left untreated, it can have serious health effects on both mother and baby. Effects on the baby include a larger size and weight at birth, which increases the risk of birth injury. For the mother, there is an increased risk of low blood glucose levels and delivery complications.
Is my baby at risk if I have diabetes?
Having any form of diabetes during pregnancy (gestational diabetes, type 1 diabetes or type 2 diabetes) increases the risk of problems for your unborn baby. Your baby may be at risk of having abnormalities at birth, being larger at birth (which increases the risk of a complicated labor, birth injuries and caesarean section), being stillborn and/or needing hospital care. However, these risks can be reduced by regularly monitoring the mother's blood sugar levels and keeping them under control.

Related topics

Cholestasis of pregnancy

Cholestasis is a condition in which the flow of bile from a pregnant woman’s liver is slowed, causing a build-up of bile acids in the bloodstream. It may occur in the later stage of pregnancy and the most notable symptom is intense itching.

Diabetes insipidus

Diabetes insipidus (DI) is caused by a chemical imbalance that hinders the body’s ability to control its fluids. It can cause people to become very thirsty and pass large amounts of urine. If left untreated, the condition can cause life-threatening dehydration.

Diabetic ketoacidosis

Diabetic ketoacidosis (DKA) is a life-threatening condition caused by a build-up of waste products called ketones in the blood. It occurs in people with diabetes when they have no – or very low levels of – insulin. DKA is most commonly seen in people with type 1 diabetes.

Ectopic pregnancy

An ectopic pregnancy occurs when an embryo begins to develop at a site other than within the uterus, such as in a fallopian tube. Unfortunately, it results in the loss of the pregnancy. If left untreated, an ectopic pregnancy can cause dangerous complications, such as haemorrhage into the abdomen.

About this article

Title: Gestational diabetes

Author: Kellie Heywood

First Published: 27 Nov 2014

Last reviewed: 17 Jan 2022

Category: Information on Gestational diabetes

Average rating: 5.0 out of 5 (1399 votes)

Processing your vote now...

Sorry your vote failed to process.

Rate this report below.

Feel like sharing?

X

Your privacy

We use cookies to improve our website and service. By continuing to browse this website you accept the use of cookies by us and our partners. If you require more information please read our privacy policy and terms and conditions before proceeding.