Association of Pre-pregnancy low-carbohydrate diet with maternal oral glucose tolerance test levels in Gestational Diabetes

Background: Limited evidence exists on the correlation between the pre-pregnancy low-carbohydrate (LC) diet and maternal oral glucose tolerance test (OGTT) levels during pregnancy. Our aim was to compare the differences in maternal OGTT levels among women who had been diagnosed with gestational diabetes mellitus (GDM) during pregnancy and adopted different dietary patterns in the pre-pregnancy period. Methods This was a case-control study in 20 GDM women with LC diet during pre-conception (LC/GDM), using 80 GDM women with conventional diet (Con/GDM) and 80 women with conventional diet but without GDM as reference (Con/Healthy), respectively. Potential risk factors of GDM were controlled. We used unadjusted raw data to compare the dietary composition data and biomarkers of the three study groups. Results Compared with the Con/GDM group, the OGTT-1h and OGTT-2h values in LC/GDM group were significantly higher (10.36 ± 1.28 mmol/L vs. 9.75 ± 0.98 mmol/L; 9.12 ± 0.98 mmol/L vs. 8.29 ± 1.06 mmol/L). Furthermore, 40% of the LC/GDM group participants had abnormal values in both OGTT-1h and OGTT-2h, significantly higher than 16.3% of the Con/GDM group. Conclusions We observed a relationship between the pre-pregnancy LC diet and more detrimental OGTT values in patients with GDM. This finding warrants further studies to understand the effect of pre-pregnancy LC diet behavior on maternal glucose tolerance.