January 2015 Issue

Break the Cycle of Gestational Diabetes
By Beth W. Orenstein
Today's Dietitian
Vol. 17 No. 1 P. 52

Controlling the disease as early in pregnancy as possible will benefit the health of mother and baby in years to come.

According to the Centers for Disease Control and Prevention, the prevalence of gestational diabetes mellitus (GDM) is as high as 9% among pregnant women.1

Laura Hieronymus, MSEd, RN, MLDE, BC-ADM, CDE, FAADE, a doctor of nursing practice candidate from the University of Kentucky, who gave a presentation on GDM and its effects on family health at the American Association of Diabetes Educators (AADE) Annual Meeting in Orlando in August 2014, says "GDM is the most common medical problem in pregnancy."

Around the 16th week during a normal pregnancy, the body starts to require more insulin to ensure blood glucose enters the body's cells. When a woman is pregnant, the hormones produced by the placenta can create insulin resistance. "As you progress through pregnancy, the central abdominal weight increases, which is characteristic of weight [gain] that can lead to insulin resistance," Hieronymus says. Most pregnant women will produce greater amounts of insulin adequate to control blood glucose levels. But in some women, around the 24th to 28th week of pregnancy, insulin production can't keep up and they're unable to overcome that insulin resistance. These women typically develop GDM.

Some women are at greater risk of GDM; it occurs more frequently among blacks, Hispanics, Asians, and Native Americans, Hieronymus says.2 Other risk factors include age, weight, medical history, family history of diabetes, presence of polycystic ovary syndrome, and previous history of delivering a large-for-gestational-age baby, says Vandana Sheth, RD, CDE, a dietitian in the Los Angeles area and spokesperson for the Academy of Nutrition and Dietetics (the Academy). Inactivity also is a risk factor, says Jessica Crandall, RD, CDE, a Denver-based dietitian and a national spokesperson for the Academy. Exercise enables the body to use glucose without extra insulin, according to the American Diabetes Association. However, Sheth says, many women who develop GDM have no known risk factors.

Getting Tested
Women who are at high risk of GDM should be tested as early as possible during the first trimester, says Melissa Joy Dobbins, MS, RDN, CDE, an AADE spokesperson who's been a diabetes educator for more than 15 years and has worked in a high-risk obstetrics clinic. Otherwise, obstetricians routinely test women at 24 to 28 weeks gestation. To test for diabetes, women are given a syrupy solution to drink. One hour later, blood is drawn to measure their blood glucose level. If it's above 130 to 140 mg/dL, they will be given an oral glucose tolerance test. This test involves fasting for eight hours and then drinking a sugary beverage. Blood glucose levels are tested one, two, and possibly three hours later, according to the National Diabetes Information Clearinghouse.

Women need to know whether they have GDM so they can watch their diets and schedule physical activity into their day. Treatment for GDM is crucial, Crandall says, because high blood glucose can lead to larger babies (greater than 9 lbs), which can make delivery more challenging and possibly result in complications. Some obstetricians recommend daily blood glucose testing and insulin injections.

In most cases, GDM disappears with the birth of the baby, Hieronymus says. However, its effects on the mother and child can last a lifetime. Women with GDM are at a 60% increased risk of developing type 2 diabetes later in life, Dobbins says. They have a 50% to 75% higher risk if they're obese, Hieronymus says. Women who develop GDM during their first pregnancy are 60% to 70% more likely to develop the condition with any future pregnancies.2 Not only is the mother at greater risk, but her child also has a greater chance of becoming obese and developing type 2 diabetes later in life, she says. A study published in Diabetes Care in October 2014 found that women who developed GDM and who were overweight before they conceived were at higher risk of having daughters who become obese.3

Dietary Strategies
GDM presents challenges and opportunities for dietitians and diabetes educators, Hieronymus says. Dietitians can play an important role by helping women with GDM and their family members to make healthful food choices. Meal plans should include a variety of foods, particularly fresh fruits and vegetables, and fat intake should be less than 30% of daily calories. It's also important that mothers who are at risk of developing type 2 diabetes get the recommended 14 g of dietary fiber/1,000 kcal.

Dobbins says diets for GDM are individualized, but in the clinic where she worked the diabetes educators generally recommended pregnant women with GDM eat three small meals plus three snacks throughout the day. Carbs typically were 40% to 45% of total calories and at least 175 g per day. The recommended bedtime snack included fat and protein and 30 g of carbohydrate. How many calories a woman with GDM needs depends on her BMI and activity level. Pregnant women are encouraged to consume about 300 kcal more per day during the second and third trimesters to support appropriate weight gain and fetal development.

Recommended weight gain during pregnancy also depends on the woman's starting BMI, according to the Institute of Medicine. Women who are underweight with a BMI of 18.5 or less should gain 28 to 40 lbs; normal weight women with a BMI of 18.5 to 24.9 should gain 25 to 35 lbs; overweight women with a BMI of 25 to 29.9 should gain 15 to 25 lbs; and obese women with a BMI greater than or equal to 30 should limit weight gain to 11 to 20 lbs. "The goal is to provide as much flexibility in the diet and as little restriction as possible while getting blood glucose results in the acceptable range," Dobbins says. "If the blood glucose goals aren't being met, then we encourage more dietary changes and graduate to insulin as needed."

Hieronymus recommends families eat together and have light and fun conversations. "When families eat meals together, data show it increases the consumption of healthful foods,"4 she says. It's also a good idea to get the entire family involved in food preparation and cleanup to promote healthful habits, she adds. Crandall says she likes to focus on how a diabetes prevention diet can be healthful for everyone in the family "as well as a great new lifestyle to introduce to your family for long-term health."

Dietitians also can teach family members about appropriate portion sizes to prevent weight gain. Hieronymus suggests families also try a new "slimmed down" recipe each week to reduce calories to help maintain a healthful weight. "Eating right and getting regular physical activity during pregnancy can help you control your gestational diabetes and have a healthy baby," Sheth says, "but it can also be the foundation of a healthful lifestyle for your family." Fortunately, she says, most women with GDM are highly motivated to eat right and exercise regularly. "They recognize the importance of healthful eating and physical activity as a positive way of significantly impacting their baby and themselves."

Breakfast Is the Most Important Meal
Due to pregnancy hormones, women with GDM seem to have the hardest time controlling their blood sugar in the morning, Dobbins says. Therefore, dietitians should encourage women to focus on breakfast choices that will support better blood glucose control. These may include fewer carbohydrates with an emphasis on whole grains that provide fiber such as oatmeal, protein from eggs, lean meats such as turkey sausage, low-fat cheeses and other dairy products, and fresh fruit (rather than juice). They can add nonstarchy vegetables such as broccoli, tomatoes, or spinach to an omelet. Because of the carbohydrate content, an otherwise healthful breakfast of cereal and milk typically is discouraged.

Women who have GDM should have their blood sugar levels checked six weeks after delivery to see whether they have returned to normal, Sheth says. "Breast-feeding is also highly encouraged as it can help new mothers better manage their blood glucose levels and provide their infant with the best nutrition."5

— Beth W. Orenstein is a freelance health writer living in Northampton, Pennsylvania.

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.

2. Geil P, Hieronymus L. Gestational diabetes mellitus (GDM) — The family ties that bind. Presented at: American Association of Diabetes Educators Annual Meeting; August 8, 2014; Orlando, FL. https://s3.amazonaws.com/v3-app_crowdc/assets/events/mWoExTXqUv/activities/F03_Geil.original.1407507349.pdf

3. Kubo A, Ferrara A, Windham GC, et al. Maternal hyperglycemia during pregnancy predicts adiposity of the offspring. Diabetes Care. 2014;37(11):2996-3002.

4. Larson N, MacLehose R, Fulkerson JA, Berge JM, Story M, Neumark-Sztainer D. Eating breakfast and dinner together as a family: associations with sociodemographic characteristics and implications for diet quality and weight status. J Acad Nutr Diet. 2013;113(12):1601-1609.

5. Gunderson EP. Impact of breastfeeding on maternal metabolism: implications for women with gestational diabetes. Curr Diab Rep. 2014;14(2):460.