The Relationship between a High Carbohydrate Diet and Oral Glucose Tolerance Test in Pregnancy

The aim of this study is to examine the impact of carbohydrate ratios in the diet consumed one day prior to the 75-g oral glucose screening test on both the screening test values and the diagnosis of gestational diabetes mellitus in the unselective pregnant population.

83 pregnant women who were under observation in the antenatal clinic of our hospital and underwent glucose tolerance tests were included in the study. The patients were given training by a dietitian to keep nutrition records of the day prior to glucose loading during their previous visits before any glucose loading. A carbohydrate intake of 40-60% was considered as the normal range in terms of the percentage of carbohydrates in the diet. A carbohydrate percentage above 60% was considered to be a high carbohydrate intake. The carbohydrate percentages in their diet over the past 24 hours was compared with the effect on the glucose tolerance test.

Out of the 83 pregnant women included in the study, 40 of them had a high carbohydrate diet (HCD) prior to the oral glucose tolerance test (OGTT), and the average carbohydrate percentage of this diet was found to be 62%. The remaining 43 patients had an average carbohydrate percentage of 49% and belonged to the group that had a normal carbohydrate diet (NCD). Out of the 83 pregnant women, 33 of them were at high risk for gestational diabetes mellitus (GDM). In the high-risk patient group, 16 patients had an NCD intake, while 17 patients had a HCD intake. It was determined that a high carbohydrate diet had no significant effect on fasting, first-hour, and second-hour glucose levels, as well as the diagnosis of gestational diabetes mellitus (GDM), in both the unselective population and the high-risk patient population.

In our study, we concluded that the high carbohydrate ratios in the diets of pregnant women one day prior did not affect the OGTT results or the GDM ratios. This indicates that there is no need for a preparatory diet prior to the OGTT in women with normal dietary habits.