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 (β=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.