Gestational diabetes mellitus (GDM) can cause high blood sugar levels in pregnant women. It may also affect the children born to GDM affected diabetic women. Studies show that an appropriate diet with a low glycemic index (GI) foods, high fiber, and high protein can be helpful in managing blood glucose levels.
Hyperglycemia is one of the prevalent medical conditions observed in pregnant women. The International Diabetes Federation reported that 16.8% of the children born live are to women with pregnancy-related hyperglycemia, of which 84% is induced by gestational diabetes mellitus (GDM).
GDM is defined as recognition or onset of carbohydrate intolerance during pregnancy irrespective of therapy or diet. The prevalence of GDM varies in India; ranging from 6%-9% in the rural population to 12%-21% in the urban population. Moreover, it is estimated that at any given time point about 4 million women are affected by GDM in India. High risk of impaired glucose tolerance (IGT) is observed in women with GDM and are more likely to develop type 2 diabetes mellitus (T2DM) in the years following pregnancy.
Children born to women with GDM are prone to obesity, IGT and diabetes in childhood and prior adulthood. GDM is associated with increased maternal, perinatal, and neonatal morbidity. These include:
- Increased C-section deliveries (which varies from 30-40%)
- Preeclampsia and subsequent development of T2DM
- Birth trauma
- Shoulder dystocia
- Birth injury to the neonate
- Hypoglycemia in the neonate
- Hyperbilirubinemia in the neonate
- Respiratory distress syndrome in the neonate
- Risk of childhood obesity and diabetes later in life
There is significant evidence suggesting the increasing vulnerability to diabetes and cardiovascular disorders in mothers. Evidence also exists indicating the role of in-utero imprinting on elevating the risks of diabetes and cardio-metabolic disorders in children born to mothers with hyperglycemia in pregnancy. This creates a need for a global focus on prevention, screening, diagnosis, and management of hyperglycemia during pregnancy. Hence, the International Federation of Gynecology and Obstetrics (FIGO) organized a group of international experts to document issues and suggest solutions for the management of GDM.
Diabetes in Pregnancy Study Group of India (DIPSI) and FIGO recommends screening of all pregnant women during the 1st trimester and between 24-28 weeks of gestation with a single-step procedure to diagnose GDM.
- Measure fasting/non-fasting 2-hr value after 75g-OGTT
- Diagnosis is best using venous plasma sample, but using a calibrated hand-held glucometer is also acceptable
- Reading between 7.8-11.0 mmol or 140-199 mg/dl indicates GDM
Medical Nutrition Therapy (MNT) plays a crucial role in managing GDM and also significantly affects women and neonates. MNT focusses on ensuring acceptable weight gain during pregnancy and fetus growth with maintained euglycemia. A diet with optimum energy content and macronutrient distribution is important. The classical intervention restricts the intake of carbohydrates, however, the recent evidence favors a low-glycemic index diet in pregnancy.
Glycemic Index (GI) is used to rank carbohydrate-containing foods based on their ability to raise blood glucose levels as compared with a reference food. It is a tool that is used to understand the blood glucose response of different carbohydrate-containing foods. Thus, GI enables the appropriate selection of foods. According to Riccardi et al., low GI foods have consistently shown a beneficial effect on blood glucose control in both the short and long term in people with diabetes.
GI uses a scale of 0 to 100, with higher values representing foods that cause the most rapid rise in blood glucose levels. The GI of foods is classified as low GI (<55), medium GI (56-69) and high GI (>70). The GI of food has been developed to compare the physiological effects of carbohydrates on glucose.
Dietary proteins are considered low in GI in nature and may be beneficial in diabetes management. Research suggests that increasing protein may help in improving insulin sensitivity, increase satiety, and help in weight management in people with diabetes. In women with GDM, studies suggest that a low GI diet is associated with:
- Decrease in postprandial glucose
- Reduced insulin usage
- Decrease in risk of macrosomia
- Decrease in risk of C-section delivery
The Recommended Dietary Allowances of protein for non-pregnant, non-lactating women is 55 g/day. This protein requirement can be met by adequate consumption of protein-rich foods like meat, egg, fish, poultry, dairy products, soy, pulses, dals, and nuts. There is ~50% increase in the need for protein during pregnancy (82.2 g/day) and lactation (77.9 g/day). Approximately 90% of Indian pregnant women’s diet is found to be protein deficient and their recommended protein needs are not being met. This demonstrates that Indian women are unable to fully meet the additional demands of pregnancy and lactation through diet alone. One way by which the protein gap can be bridged is through the use of nutritional supplements that provides good quality protein along with other vital nutrients. In women with GDM, it is important that the supplement used provides high protein and also have low GI, which has been shown to have beneficial effect in controlling blood glucose fluctuations. Additionally, presence of good amount of fiber would be an added advantage since fiber has been associated with improved glycemic control and weight management.
Hence, to minimize and prevent the maternal and fetal complications associated with GDM, it is important that the diet is given special attention and appropriate nutritional supplements are given as described above.