AIMS: To secure adequate carbohydrate supply in pregnancy, the Institute of Medicine (IOM) recommends a minimum amount of carbohydrates of 175 g daily. Currently a low carbohydrate diet is a popular health trend in the general population and this might also be common among overweight and obese pregnant women with type 2 diabetes (T2D). Thus, we explored carbohydrate consumption among pregnant women with T2D including women with type 1 diabetes (T1D) for comparison.

METHODS: A retrospective cohort study of consecutive women with T2D (N = 96) and T1D (N = 108), where dietary records were collected at the first antenatal visit.

RESULTS: Among women with T2D and T1D, bodyweight at the first visit was 90.8 ± 22 (mean ± SD) and 75.5 ± 15 kg (P < 0.001) while HbA1c was 6.6 ± 1.2% (49 ± 13 mmol/mol) and 6.6 ± 0.8% (48 ± 8 mmol/mol), P = 0.8, respectively. The average daily carbohydrate consumption from the major carbohydrate sources was similar in the two groups (159 ± 56 and 167 ± 48 g, P = 0.3), as was the level of total daily physical activity (median (interquartile range)): 215 (174-289) and 210 (178-267) metabolic equivalent of task-hour/week (P = 0.9). A high proportion of women with T2D and T1D (52% and 40%, P = 0.08) consumed fewer carbohydrates than recommended by the IOM. The prevalence of ketonuria (≥4 mmol/L) was 1% in both groups.

CONCLUSIONS: In early pregnancy, a lower daily carbohydrate consumption than recommended by the IOM was common among women with T2D. The results were quite similar to women with T1D, despite a markedly higher bodyweight in women with T2D. Reassuringly, ketonuria was rare in both groups.