Managing Gestational Diabetes with the Right Diet

Gestational diabetes (GDM) is a form of glucose intolerance first diagnosed during pregnancy. Approximately 7% of all pregnancies are complicated by GDM, and women who have had GDM have a 20% to 50% chance of developing diabetes in the next 5 to 10 years.

Risk for GDM:

• Obesity (BMI >30.0)

• Personal history of GDM

• Glycosuria

• Strong family history of diabetes (1st degree relative)

• Prior poor obstetrical outcome (stillbirth, birth defects)

• Member of a high-risk ethnic group (Hispanic, African American, Native American, South or East Asian, Pacific Islander)

During the second or third trimesters of pregnancy, metabolic alterations occur to meet maternal and fetal energy and nutrient demands. In addition to alterations in insulin secretion, these alterations affect glucose, amino acid, and lipid metabolism. Although most women with GDM revert to standard glucose tolerance postpartum, there is an increased likelihood of developing GDM in subsequent pregnancies and T2DM later in life. Increasing physical activity and reducing postpartum weight gain can reduce the risk of subsequent diabetes.

Maternal complications associated with GDM include hypertension (preeclampsia), polyhydramnios, difficult birth, preterm delivery (before 38 weeks of gestation), and a higher rate of cesarean sections. Fetal and neonatal complications include macrosomia, hypoglycemia, respiratory distress syndrome, hypocalcemia, hyperbilirubinemia, and polycythemia.

Adequate energy is necessary for desirable weight gain during pregnancy.

Energy needs should be indirectly evaluated by monitoring the woman’s physical activity, appetite, food intake, blood glucose levels, ketone levels, and weight changes, with the help of a dietitian.

It is not necessary to calculate energy needs unless excessive weight loss or gain is observed.

Protein requirements should be increased during the second and third trimesters of pregnancy to 25 grams per day or 1.1 g protein per kg desirable body weight. Two factors are very important regarding fat intake during pregnancy: impact on the woman’s body weight and plasma lipoprotein profiles. Reduced fat intake may be necessary if total energy intake is decreased, and saturated fat, trans fat, and cholesterol intake should be curtailed.

Consequences of folate deficiency in pregnancy (i.e., neural tube defects) have been well documented. All women of reproductive age capable of becoming pregnant should take 400mcg of additional folate daily from food or supplements. Whereas about 10% of the iron is absorbed from food in the non-pregnant state, iron absorption increases to 25% at the beginning of the second trimester. Supplementation of 30 mg ferrous iron in the second and third trimesters is recommended.

Nutrients recommended during pregnancy.

Nutrient or Food Type	Recommendation	Meal-Planning Tips
Energy	Intake should be sufficient to promote adequate, but not excessive, weight gain and to avoid ketonuria.	Include 3 small- to moderate-sized meals and 2–4 snacks. Space snacks and meals at least 2h apart. A bedtime snack (or even a snack in the middle of the night) is recommended, to diminish the number of hours fasting.
Carbohydrate	Recommendations are based on effect of intake on blood glucose levels. Intake should be distributed throughout the day. Frequent feedings, smaller portions, with intake sufficient to avoid ketonuria.	Common carbohydrate guidelines: 2 carbohydrate choices(15–30 g) at breakfast, 3–4 choices (45–60 g) for lunch and evening meal, and 1–2 choices (15 to 30 g) for snacks. Recommendations should be modified based on individual assessment and blood glucose self-monitoring test results.
High-Sucrose/High-Energy Foods	Inclusion should be based on individual’s ability to maintain blood glucose goals, nutritional adequacy of diet, and contribution of these foods to total meal plan.	Eliminate foods containing large amounts of carbohydrates, such as sweets and sweetened drinks.
Protein	DA for adult women (0.8 g/kg DBW) _ 25 g/day, or 1.1 g/kg DBW.	Protein foods do not raise post-meal blood glucose levels. Add protein to meals and snacks, to help provide enough calories and to satisfy appetite.
Fat	Limit saturated fat.	Fat intake may be increased because of increased protein intake; focus on leaner protein choices.
Sodium	Not routinely restricted.
Fiber	For relief of constipation, gradually increase intake and increase fluids.	Use whole grains and raw fruits and vegetables. Activity and fluids help relieve constipation.
Nonnutritive Sweeteners	Generally safe in pregnancy. Use in moderation.	Saccharin crosses the placenta but has not been shown to be harmful.
Vitamins and Minerals	Inclusion should be based on an individual’s ability to maintain blood glucose goals, nutritional adequacy of diet, and contribution of these foods to the total meal plan.	Take prenatal vitamin. If it causes nausea, try taking at bedtime.
Caffeine	Limit to <300 mg/day.
Alcohol	Avoid.	Inclusion should be based on an individual’s ability to maintain blood glucose goals, nutritional adequacy of diet, and the contribution of these foods to the total meal plan.