Interpretation
Over the past decades, the prevalence of obesity and diabetes mellitus has increased robustly, and both have become serious health problems worldwide. 3 According to the International Diabetes Federation, 1 in 6 live births, approximately 20 million, is affected by hyperglycemia during pregnancy, with 84% of mothers having gestational diabetes. 22 Compared to general diabetes, GDM has more significant clinical implications in that it can influence both neonates and mothers. Although numerous studies have been conducted on diagnostic criteria, treatment targets, and prognostic factors, many of these findings remain controversial.
Several previous reports have investigated the association between the AUC of the OGTT and pregnancy outcomes. Kim et al. reported that the AUC for the 100-g OGTT was associated with an increased risk of LGA in GDM.23 Another study from China demonstrated that a higher AUC for the 75-g OGTT was related to adverse pregnancy outcomes, such as hypertensive disease and macrosomia. 24 Our study findings are consistent with these results, demonstrating that hyperglycemia itself is an important pitfall for adverse perinatal outcomes though a more meticulous analysis of the OGTT results. It is also necessary to explain why primary cesarean section (CS) was not included as an adverse pregnancy outcome in our study. Most of the GDM patients (85.2%, 219/257) had undergone primary CS because of the unique situation in Korea, where CS is generally preferred by pregnant women, and health service accessibility is very high.
We clustered all subjects based on the LPA, presenting specific patterns such as impaired fasting glucose-like pattern, impaired glucose tolerance-like pattern, and combined patterns (Fig. 1 ), since we initially expected the OGTT patterns reflecting the individual insulin response to play an important role in adverse pregnancy outcomes. However, we did not find significant associations between OGTT patterns and pregnancy outcomes. We postulate that hyperglycemia itself is a matter of substance because the number of abnormal values and AUCs during the 100-g OGTTs were independent risk factors for adverse pregnancy outcomes. Moreover, the ORs for three and four abnormal values in Table 3 slightly decreased after additional adjustment for treatment-related factors in Model 2, underpinning the importance of hyperglycemic control and related risk factor management.