Gestational Diabetes

Gestational diabetes, or diabetes that occurs in the second and third trimester of pregnancy and resolves at birth, occurs in approximately 9.2 percent of pregnancies in America.

Gestational diabetes is defined as impaired glucose tolerance with onset or first recognition during pregnancy.  It occurs in women who have never had diabetes before but who develop high sugar levels during pregnancy.

Similar to other types of diabetes, gestational diabetes affects how your cells use glucose.  It causes high blood sugar that can affect your pregnancy and your baby.

While gestational diabetes can be an alarming complication, it can be controlled by maintaining a healthy diet, exercising, and taking medication if needed.  A mother’s blood glucose levels usually return back to normal after delivery.  However, she should be closely monitored by her health care provider.

You will probably be tested for gestational diabetes between weeks twenty-four and twenty-eight of your pregnancy, using an oral glucose tolerance test to see how well your body responds to ingesting a large amount of glucose. If you have a higher risk of gestational diabetes, your doctor may test you earlier, at your first visit during your pregnancy.

Causes of Gestational Diabetes:

Researchers don’t know exactly what causes gestational diabetes and why some women develop it.  However, it’s helpful to know what happens in the body when a woman does develop gestational diabetes.

According to the Mayo Clinic, the placenta produces high levels of various hormones which many of which impair the action of insulin within the body’s cells.  As the baby grows, the placenta produces more and more insulin-countering hormones.

In gestational diabetes, the placental hormones create a rise in blood sugar that can affect the growth and health of your baby.  The condition usually develops during the last half of pregnancy.

Potential Risk Factors:

Some known risk factors for gestational diabetes include the following:

• Family history- if a parent or sibling has type 2 diabetes
• Personal history- if you have a history of prediabetes or
• Women who are pregnant and over the age of 25 are more likely to develop gestational diabetes
• Overweight with a body mass index of 30 or higher
• Having had gestational diabetes in a previous pregnancy
• Having prediabetes
• Having given birth previously to a child weighing nine pounds or more
• Having polycystic ovarian syndrome (PCOS)
• In addition, the same populations at risk for type 2 diabetes—Latino Americans, African Americans, Pacific Islanders, and Asian Americans—are also at greater risk for gestational diabetes.

Symptoms:

For most women, gestational diabetes doesn’t cause any symptoms.  However, gestational diabetes screening is part of normal prenatal care.  If you develop gestational diabetes, you will have more frequent check-ups.

Diagnosis:

According to Mayo Clinic, medical experts haven’t agreed on screening guidelines.  Your doctor will evaluate your risk factors for gestational diabetes early in your pregnancy.  If you have risk factors for gestational diabetes, your doctor will evaluate when screening is right for you.

Routine screening for gestational diabetes involves an oral glucose test.  The test involves drinking a sweetened liquid, called Glucola, which contains 50 g of glucose.  How the body metabolizes this solution is measured by a blood test.  A blood sugar level below 130 to 140 mg/dL, is usually considered normal on a glucose challenge test.

A blood sugar level higher than 140 mg/dL, will identify 80% of women with gestational diabetes.  When the threshold is lowered to 130 mg/dL, 90% of women will be identified.  If your blood glucose level is greater than 130 mg/dL, your doctor will recommend you to take another screening test that will require fasting before the test.

Complications of Gestational Diabetes:

Women who develop gestational diabetes have problems metabolizing glucose. Their pancreas produces plenty of insulin (the hormone responsible for “unlocking” cells so that glucose can enter them and provide energy), but a condition known as insulin resistance prevents them from using it effectively. When insulin doesn’t work properly, blood glucose (or blood sugar) builds up in the bloodstream, and gestational diabetes is the result.

The fetus of a woman with gestational diabetes may become larger as it stores the excess glucose it is receiving from the mother as fat, a condition known as macrosomia. A large infant may have a more difficult time descending the birth canal. Other potential risks for the baby include hypoglycemia (low blood sugar) and jaundice. A pediatrician or a neonatologist, a physician who specializes in high-risk infant care, is often present at the births of gestational-diabetes babies to handle any potential complications.

Women who are able to effectively manage their gestational diabetes and keep blood glucose levels in the safe range dramatically reduce the risk of pregnancy complications. Potential pregnancy complications of uncontrolled gestational diabetes include:

• Hypertension. High blood glucose levels can cause high blood pressure; hypertension in pregnancy can lead to a dangerous complication known as preeclampsia.
• Preeclampsia. If high blood pressure becomes severe, preeclampsia may develop. Other signs of preeclampsia include protein in the urine and severe edema (swelling). The only treatment for preeclampsia is delivery of the baby, which may mean a premature birth.
• Increased risk for developing gestational diabetes in subsequent pregnancies, and type 2 diabetes in the future.

Treatment and Prevention:

Gestational diabetes requires treatment with dietary changes, exercise, and/or insulin injections to keep maternal blood glucose levels as close to normal as possible, and to prevent complications in both mother and baby. Women with gestational diabetes are also encouraged to self-test their blood glucose levels often.

There’s no surefire way to ensure the prevention of gestational diabetes, but preconception planning may help to facilitate prevention by reducing some of the risk factors associated with gestational diabetes, such as excess weight.

Strategies known to improve insulin resistance, and that may make a difference in the development of gestational diabetes, include:

• Maintaining a healthy weight
• Staying active
• Eating right

If you’re planning a pregnancy, talk to your doctor about your gestational diabetes risk and how to lower it.

Gestational Testing Goals:

If you have gestational diabetes, regular blood sugar checks are important to the health of you and your baby. Talk to your doctor about your specific target goals for testing and how to reach them. The American Diabetes Association’s general guidelines for blood sugar checks are:

• Before a meal (preprandial/fasting blood glucose level—lower than 95 mg/dl (5.27 mmol/L)
• One hour after a meal (postprandial/lower than 140 mg/dL (7.77 mmol/L)
• Two hours after a meal (postprandial/lower than 120 mg/dL (6.66 mmol/L)

What to Eat?

A balanced and healthy diet is important during and after pregnancy and will help control blood glucose levels.  A diet rich in the following foods can help you maintain healthy blood sugar levels and also provide proper nutrition for both you and your baby.

It’s important to monitor how many and what kinds of carbohydrates you consume as well.  Keeping a food log may be a helpful way to monitor your carb intake.

The American Diabetes Association recommends that women with gestational diabetes should eat three small to moderate meals and two to four snacks per day.  The ADA recommends that an evening snack may be needed to prevent accelerated ketosis overnight.

Foods to Eat for a Balanced Diet:

• Vegetables
• Non-fat dairy products
• Fruits
• Whole grains
• Lean meats
• Fish
• Eggs
• Poultry

Eating more protein helps to balance blood glucose levels.  These foods include fish, chicken, turkey, eggs, tofu, beans, nuts, seeds, quinoa and legumes or lentils.

Foods to Avoid if Diagnosed with Gestational Diabetes:

• Cakes
• Biscuits
• Sweets
• Puddings
• Soda
• Fruit juice with added sugar
• White potatoes
• White bread
• White rice
• White pasta

Being diagnosed with gestational diabetes may be worrisome, but with a strong plan in place to manage your blood glucose levels, and some dedication and discipline, it’s possible to make it through pregnancy with you and your child unaffected.

Make sure you work with your doctor and a dietician to monitor and maintain your weight and body mass index (BMI) throughout your pregnancy.

Testing may be done a few months after pregnancy to make sure blood glucose levels have returned to normal.  It is possible to have an increased risk of developing type 2 diabetes later in life, so make sure you consult your doctor to have regular screenings.

Updated by Julia Telfer, MPH, 10/16.

Sources:

1. DeSisto CL, Kim SY, Sharma AJ. Prevalence Estimates of Gestational Diabetes Mellitus in the United States, Pregnancy Risk Assessment Monitoring System (PRAMS), 2007–2010. Prev Chronic Dis 2014;11:130415. DOI:http://dx.doi.org/10.5888/pcd11.130415.
2. Mayo Clinic.  “Gestational Diabetes.” Accessed March 15, 2018.  https://www.mayoclinic.org/diseases-conditions/gestational-diabetes/symptoms-causes/syc-20355339
3. American Diabetes Association.  “Nutrition Principles and Recommendations in Diabetes.” Diabetes Care 2004 Jan; 27 (suppl 1): s36-s36. https://doi.org/10.2337/diacare.27.2007.S36
4. Hippokratia.  “Gestational diabetes mellitus: why screen and how to diagnose.” Accessed March 15, 2018.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2943351/
5. American Diabetes Association. “How to Treat Gestational Diabetes.” June 7, 2013. Last updated April 29, 2014. http://www.diabetes.org/diabetes-basics/gestational/how-to-treat-gestational.html.
6. American Diabetes Association. “Standards of Medical Care in Diabetes—2016.” Diabetes Care. January 2016. Volume 39, Supplement 1: S1-S112. http://care.diabetesjournals.org/content/suppl/2015/12/21/39.Supplement_1.DC2/2016-Standards-of-Care.pdf.
7. DeSisto, C. L., S. Y. Kim, and A. J. Sharma. “Prevalence Estimates of Gestational Diabetes Mellitus in the United States, Pregnancy Risk Assessment Monitoring System (PRAMS), 2007-2010.” Preventing Chronic Disease. Centers for Disease Control and Prevention. June 19, 2014. http://dx.doi.org/10.5888/pcd11.130415.
8. U.S. Department of Health and Human Services. “Gestational Diabetes.” National Institute of Diabetes and Digestive and Kidney Diseases. September 2014. Accessed September 18, 2016. https://www.niddk.nih.gov/health-information/diabetes/types/gestational.
9. American Diabetes Association. “How to Treat Gestational Diabetes.” June 7, 2013. Last updated April 29, 2014. http://www.diabetes.org/diabetes-basics/gestational/how-to-treat-gestational.html.
10. American Diabetes Association. “Standards of Medical Care in Diabetes—2016.” Diabetes Care. January 2016. Volume 39, Supplement 1: S1-S112. http://care.diabetesjournals.org/content/suppl/2015/12/21/39.Supplement_1.DC2/2016-Standards-of-Care.pdf.
11. DeSisto, C. L., S. Y. Kim, and A. J. Sharma. “Prevalence Estimates of Gestational Diabetes Mellitus in the United States, Pregnancy Risk Assessment Monitoring System (PRAMS), 2007-2010.” Preventing Chronic Disease. Centers for Disease Control and Prevention. June 19, 2014. http://dx.doi.org/10.5888/pcd11.130415.
12. U.S. Department of Health and Human Services. “Gestational Diabetes.” National Institute of Diabetes and Digestive and Kidney Diseases. September 2014. Accessed September 18, 2016. https://www.niddk.nih.gov/health-information/diabetes/types/gestational.