Are There Benefits for Gestational Diabetes Mellitus in Treating Lower Levels of Hyperglycemia Than Standard Recommendations?

Objectives: The new International Association of Diabetes and Pregnancy Study Groups (IADPSG) recommendations for diagnosis of gestational diabetes mellitus (GDM) are generating discussion regarding their universal adoption. Our centre is currently using stricter GDM diagnostic criteria than those proposed by the IADPSG. Evaluation of complication rates and their predictors in our cohort may provide insight for the care of this high-risk population. Therefore, we determined complication rates and identified antepartum maternal predictors of adverse outcomes in our cohort with mild GDM.

Methods: A retrospective cohort study was performed between 2005 and 2011. It included women with and without GDM, which was diagnosed if fasting plasma glucose levels were 5.0 or above or 2-hour post 75 gram oral glucose tolerance test (OGTT) were 7.8 mmol/L or higher.

Results: A total of 3712 women, with and without diabetes, were included. Rates of macrosomia and pre-eclampsia were significantly higher in the group with GDM but were lower than the rates usually reported. Macrosomia, the need for insulin therapy or caesarean section and postpartum glucose intolerance predictors included prepregnancy body mass index, excessive gestational weight gain and OGTT screening results, although no specific threshold was found.

Conclusions: This study provides insight into GDM-related complications rates and the benefits of intervention in a large cohort of women with levels of hyperglycemia lower than those currently recommended for diagnosis of GDM. These findings suggest a continuous association between adverse outcomes and maternal hyperglycemia and highlight the important role of maternal risk factors other than glycemic results in the development of pregnancy-related complications. Milder forms of hyperglycemia that would not be identified by IADPSG guidelines may benefit from treatment.