Prevalence of gestational diabetes mellitus and results of the screening tests at a tertiary referral center: A cross-sectional study

Abstract

ObjectiveThis study aimed to identify the gestational diabetes mellitus (GDM) prevalence of low risk pregnant population at a tertiary referral center by different approaches. Material and methodsA cross-sectional study using retrospective data between 2007-2017 was conducted. During this period 77227 patients underwent either two step or one step glucose tolerance tests. ResultsThe median age of the study population was 27 (15–49). Fasting plasma glucose (FPG) testing was evaluated in 144,113 women at the initial antenatal care visit which %21 of these were between 92-126 mg/dL. Of these women %1.25 had FPG>126 mg/dL which showed the prevalence of pregestational diabetes in our cohort. During the study period 74412 women underwent 50-g glucose challenge test where %18 were screen positive and % 2.9 was defined as gestational diabetic without need for further testing (>180 mg/dL). The screening positive patients were sent to 100-g oral glucose tolerance test and the prevalence of GDM with two-step screening was 5.5%. A total of 2815 patients were screened by 75-g glucose tolerance test and the prevalence of GDM with one-step screening was 21%. Overall 4684 patients have been diagnosed as gestational diabetes mellitus with the prevalence of 6.07%. ConclusionFasting plasma glucose >92 mg/dL is challenging in our population due to improper fasting. The FPG dependent GDM prevalence is almost four times higher than two-step glucose screening test results (21.8% vs 5.5%). If FPG levels will be used for diagnosing GDM then the values must be checked in a second laboratory analysis.