Beginning in the second trimester of pregnancy, hormonal changes may result in gestational diabetes. All expectant mothers should be tested for gestational diabetes during their pregnancy because unlike type 1 or type 2 diabetes, gestational diabetes only affects pregnant women who have no prior history of diabetes. (1) People who have type 1 diabetes are generally born with it, while type 2 occurs in adulthood and is triggered by lifestyle factors such as obesity. (2) Gestational diabetes only develops in pregnant women who have never had diabetes before, but have high blood sugar during pregnancy. (1) If treated, the condition typically resolves after the baby is born, but can leave women at an increased risk for developing type 2 diabetes later in life. (3) That’s why it’s important to learn the measures you can take for prevention and management.
How Does Gestational Diabetes Occur During Pregnancy?
The pancreas makes a hormone called insulin. Insulin helps the body properly use and store sugar from food you eat. This keeps your blood sugar regulated. When you’re pregnant, your placenta produces a hormone that can make it harder for insulin to work. Gestational diabetes develops when the pancreas doesn’t produce enough insulin to keep your blood sugar within a normal healthy range, resulting in high blood sugar. (1)
What Causes Gestational Diabetes?
Gestational diabetes affects nearly 14% of all pregnancies or 135,000 women a year in the United States. (3) There are risk factors that can make certain women more likely to develop diabetes during pregnancy, including genetic predisposition, obesity, and behavioral factors (such as diet and exercise.) (6)
As with type 2 diabetes, obesity is a significant risk factor for gestational diabetes.
There are several risk factors, but it is more likely if you:
1. Are overweight or gained excessive weight during pregnancy
2. Have a family history of diabetes
3. Are older than 25
4. Are of Native American, Black, Pacific Islander, Hispanic, South or East Asian, or Indigenous Australian background
5. Have had gestational diabetes during previous pregnancies
6. Gave birth to a baby weighing more than 9 pounds or had a stillborn
7. Have high blood pressure
8. Are a smoker
Although there are certain risk factors, gestational diabetes can affect any pregnant woman and does not always present with symptoms. Symptoms may include:
1. Fatigue
2. Increased thirst
3. Frequent urination
4. Increased hunger
5. Blurred vision
6. Nausea and/or vomiting
Typical pregnancy symptoms often include an increase in hunger and urination, which is not always a sign of gestational diabetes. Therefore it’s important to be tested when your doctor recommends, which is usually during the 24th and 28th week of pregnancy using a glucose tolerance test. (1)
Why Should I be Tested?
When gestational diabetes is treated throughout pregnancy, women can deliver healthy babies, but when left untreated it can lead to serious complications for both mom and baby. Pregnancy complications include preeclampsia (serious high blood pressure), preterm delivery, delivering via C-section, and developing gestational diabetes again in future pregnancies. Since babies receive nutrients from their mother during pregnancy, high blood sugar can also affect their health and lead to jaundice, breathing issues, higher rates of childhood obesity, and developing diabetes later in life. (4)
How is Gestational Diabetes Diagnosed?
Women are tested for gestational diabetes between 24 and 28 weeks of pregnancy with a standard oral glucose tolerance screening. This consists of fasting for 8-16 hours, drinking a sweet glucose drink and having a blood sample drawn one hour after to check blood-sugar levels. (7) This measures the body’s response to sugar and the results will indicate if you are producing enough insulin or not. If elevated blood-sugar levels are found, another, more thorough oral glucose tolerance test will be given. (8)
How is Gestational Diabetes Treated?
Your doctor will recommend a treatment plan to control your blood sugar levels which may include:
Diet and exercise management
Monitoring of you and your baby
Self-monitoring of blood glucose levels
Insulin therapy, if necessary
Luckily, gestational diabetes can often be managed with diet modifications and an exercise routine. A change in diet is the first step to keeping your blood sugar levels in a normal range. Your healthcare provider will make recommendations such as eating regular meals throughout the day, watching portions, and having a well rounded diet consisting of fresh fruits, vegetables, and whole grains. Although carbohydrates are necessary to fuel your body and nourishes your baby, limiting carbohydrates may be recommended because carbohydrate rich foods can make blood sugar levels spike, and it’s important that glucose levels stay in a healthy range. (9)
Additionally, exercise has many health benefits and can effectively prevent and treat gestational diabetes. Brisk walking, yoga, stationary cycling, and swimming can help reduce blood sugar levels when performed for 20 to 30 minutes, three to four times a week. (10) Exercising during pregnancy is typically safe, but it’s important that your healthcare provider first evaluate your overall health to determine an exercise program that’s right for you. (12)
When diet and exercise are not enough to manage the condition, more intensive treatment may be required, such as daily glucose testing and insulin injections. (9) Your doctor will recommend a treatment that is best for you. When blood sugar levels are well-controlled, most women deliver healthy babies without any complications.
Gestational Diabetes Complications
If gestational diabetes is diagnosed and treated effectively, the risk of complications is low. The condition goes away once the baby is born, but it leaves women with an increased risk of developing type 2 diabetes later in life. (13) Nearly half of all women diagnosed with gestational diabetes in the United States develop type 2 diabetes within 15 years. (14) Additionally, the need for insulin therapy during pregnancy has been shown to be the biggest predictor for developing type 2 later in life. (14) Elevated blood sugar during pregnancy has predicted the development of type 2 diabetes, which suggests that once you have high blood sugar your insulin resistance may continue at a similar rate postpartum. That’s why it's important to follow your doctor's exercise and nutritional recommendations even after your baby is born. (3)
Early Screening and Preventing Type 2 Diabetes Later in Life
Your obstetrician–gynecologist (ob-gyn) or other health care professional can determine your risk for developing gestational diabetes by looking at your medical history. If they have reason to believe you are high risk, your blood sugar should be tested early rather than waiting until the second half of pregnancy. If you do not have risk factors or early testing comes back normal, your blood sugar will be measured during the typical period between 24 - 28 weeks of pregnancy.
The American Diabetes Association recommends that women who had gestational diabetes have postpartum glucose testing 6-8 weeks after delivery and every 3 years thereafter. It’s also important to maintain an exercise routine, healthy diet, and normal body weight after pregnancy to help prevent developing type 2 diabetes. (3) Children born from mothers with gestational diabetes are also at greater risk, with more than 20% developing pre-diabetes or type 2 diabetes by the age of 22. (14)
The prevalence of type 2 diabetes has shown a steady increase among adults and now accounts for 95 percent of all cases of diabetes in the U.S. Increased awareness of the risk of type 2 diabetes after gestational diabetes could provide an opportunity to test and use dietary, lifestyle, and medical interventions that may prevent the onset of type 2 diabetes in women and for our future generations. (13)
This information is for educational purposes only and is not intended to replace the advice of your doctor or health care provider. Talk to your doctor about any questions or concerns you may have.
1. Kathleen Romito, Thomas M. Bailey, Adam Husney, Lois Jovanovic, Rebecca Sue Uranga, and Femi Olatunbosun, 2017 Gestational Diabetes Healthwise, GOV.BC.CA
2.National Diabetes Education Project: "About Diabetes and Pre-Diabetes."
3. Catherine Kim, Katherine M. Newton, and Robert H. Knopp, 2002
Gestational Diabetes and the Incidence of Type 2 Diabetes Diabetes Care; 25(10): 1862-1868
4. Catalano, P.M., Kirwen, T.P., Hougel-de Mouzon, S., and King, J., 2003 Gestational Diabetes and Insulin Resistance: role in short- and long-term implications for mother and fetus The Journal of Nutrition, Volume 133, Issue 5, Pages 1674S-1683S
5. Bergman and R.N., 1989 Toward a physiological understanding of glucose tolerance: minimal model approach American Diabetes Association, 51, 2207-2213
6. Bergman and R.N., 1989 Toward a physiological understanding of glucose tolerance: minimal model approach American Diabetes Association, 51, 2207-2213
7. Physiopedia contributors, 2018 Gestational diabetes Physiopedia, Page Version ID: 199956
8. ACOG. Screening and diagnosis of gestational diabetes mellitus. Committee Opinion no 504. Obstet & Gynecology. 2011;118:751–53. [PubMed] [Google Scholar]
9. Anwar A, Ahmad K, Karagianni E, and Lindow S., 2018 Medical Management of Gestational Diabetes Open Journal of Obstetrics and Gynecology, 2;8(04):400
10. Harrison AL, Shields N, Taylor NF, and Frawley HC, 2016 Exercise improves glycaemic control in women diagnosed with gestational diabetes mellitus: a systematic review Journal of physiotherapy, Issue 62 (Volume 4): pages 188-96
11. Artal R and O'toole M., 2003 Guidelines of the American College of Obstetricians and Gynecologists for exercise during pregnancy and the postpartum period British journal of sports medicine, 1;37(1):6-12 12. ACOG Committee on Obstetric Practice, 2002
Committee opinion# 267: exercise during pregnancy and the postpartum period
Obstetrics & Gynecology; 99(1): 171-3
13. Leanne Bellamy, Juan-Pablo Casas, Prof Aroon D Hingorani, and Dr David Williams, 2009
Type 2 diabetes mellitus after gestational diabetes: a systematic review and meta-analysis
The Lancet, Volume 373, Issue 9677, Pages 1773-1779
14. Anna J. Lee, Richard J. Hiscock, Peter Wein, Susan P. Walker, and Michael Permezel, 2007
Gestational Diabetes Mellitus: Clinical Predictors and Long-Term Risk of Developing Type 2 Diabetes
Diabetes Care; 30(4): 878-883