Dietary Advice to Support Glycaemic Control and Weight Management in Women with Type 1 Diabetes during Pregnancy and Breastfeeding.

In women with type 1 diabetes, the risk of adverse pregnancy outcomes, including congenital anomalies, preeclampsia, preterm delivery, foetal overgrowth and perinatal death is 2-4-fold increased compared to the background population. This review provides the present evidence supporting recommendations for the diet during pregnancy and breastfeeding in women with type 1 diabetes. The amount of carbohydrate consumed in a meal is the main dietary factor affecting the postprandial glucose response. Excessive gestational weight gain is emerging as another important risk factor for foetal overgrowth. Dietary advice to promote optimized glycaemic control and appropriate gestational weight gain is therefore important for normal foetal growth and pregnancy outcome. Dietary management should include advice to secure sufficient intake of micro- and macronutrients with a focus on limiting postprandial glucose excursions, preventing hypoglycaemia and promoting appropriate gestational weight gain and weight loss after delivery. Irrespective of pre-pregnancy BMI, a total daily intake of a minimum of 175 g of carbohydrate, mainly from low-glycaemic-index sources such as bread, whole grain, fruits, rice, potatoes, dairy products and pasta, is recommended during pregnancy. These food items are often available at a lower cost than ultra-processed foods, so this dietary advice is likely to be feasible also in women with low socioeconomic status. Individual counselling aiming at consistent timing of three main meals and 2-4 snacks daily, with focus on carbohydrate amount with pragmatic carbohydrate counting, is probably of value to prevent both hypoglycaemia and hyperglycaemia. The recommended gestational weight gain is dependent on maternal pre-pregnancy BMI and is lower when BMI is above 25 kg/m2. Daily folic acid supplementation should be initiated before conception and taken during the first 12 gestational weeks to minimize the risk of foetal malformations. Women with type 1 diabetes are encouraged to breastfeed. A total daily intake of a minimum of 210 g of carbohydrate is recommended in the breastfeeding period for all women irrespective of pre-pregnancy BMI to maintain acceptable glycaemic control while avoiding ketoacidosis and hypoglycaemia. During breastfeeding insulin requirements are reported approximately 20% lower than before pregnancy. Women should be encouraged to avoid weight retention after pregnancy in order to reduce the risk of overweight and obesity later in life. In conclusion, pregnant women with type 1 diabetes are recommended to follow the general dietary recommendations for pregnant and breastfeeding women with special emphasis on using carbohydrate counting to secure sufficient intake of carbohydrates and to avoid excessive gestational weight gain and weight retention after pregnancy.

The influence of carbohydrate consumption on glycemic control in pregnant women with type 1 diabetes.

AIMS: To study the influence of the quantity and the quality of carbohydrate consumption on glycemic control in early pregnancy among women with type 1 diabetes. METHODS: A retrospective study of 107 women with type 1 diabetes who completed 1-3days of diet recording before first antenatal visit, as a part of routine care. The total daily carbohydrate consumption from the major sources (e.g. bread, potatoes, rice, pasta, dairy products, fruits, candy) was calculated. A dietician estimated the overall glycemic index score (scale 0-7). RESULTS: At least two days of diet recording were available in 75% of the 107 women at mean 64 (SD±14) gestational days. The quantity of carbohydrate consumption from major sources was 180 (±51)g/day. HbA1c was positively associated with the quantity of carbohydrate consumption (ß=0.41; 95% CI 0.13-0.70, P=0.005), corresponding to an increase of 0.4% in HbA1c per 100g carbohydrates consumed daily, when adjusted for insulin dose/bodyweight and use of insulin pump treatment. The median (IQR) glycemic index score was 2 (0-3). An adjusted association between HbA1c and glycemic index score was not demonstrated. The women using carbohydrate counting daily (45%) had lower HbA1c compared to the remaining women (6.4 (±0.5) vs. 6.8 (±0.9)% (47±6 vs. 51±10mmol/mol), P=0.01). CONCLUSIONS: HbA1c in early pregnancy was positively associated with the quantity of carbohydrate consumption regardless of insulin treatment. Carbohydrate counting is probably important for glycemic control in pregnant women with type 1 diabetes.