403: Screening for GDM– can we use the results of the GCT of the previous pregnancy?

Abstract

To assess whether previous pregnancy glucose challenge test (GCT) result among non-diabetic women may serve in an index pregnancy. as a screening tool for Gestational Diabetes Mellitus (GDM) Retrospective study based on computerized records in a single large university medical center. All women who had a singleton pregnancy and two subsequent deliveries in our medical center between 2005 and 2017 were included. Women with Diabetes Mellitus or GDM in the previous pregnancy and women without documented GCT results in their previous pregnancy, were excluded. GDM diagnosis is based on either National Diabetes Data Group criteria or the Carpenter and Coustan criteria. Unpaired student T-test and one way ANOVA were used to asses associations between GCT levels and maternal characteristics. Multivariable logistic model was conducted to assess the independent role of GCT level at previous pregnancy on GDM at index pregnancy. ROC curves were constructed. All tests are two-sided. P value below 0.05 was considered statistically significant. Analyses were carried out using SPSS software package version 22 (IBM, Armonk, NY). A total of 31,861 women met inclusion criteria. Of those, 670 (2.1%) had GDM in the index pregnancy. Parturients with GDM in the index pregnancy had higher mean levels of GCT in the previous pregnancy in comparison to parturients without GDM (127.5±28 VS. 98.7±24 mg/dl, respectively, p<0.001). There was a positive association between GCT results in previous pregnancy and rates of GDM in index pregnancy (Figure). Multivariate analysis controlling for known risk factors for GDM revealed that GCT levels in previous pregnancy were independently associated with rates of GDM in index pregnancy (1.04, 95% CI 1.03-1.04, p<0.001). Using a GCT value of 107 mg/dl (65th percentile), the area under the ROC curve was 0.79, suggesting a fair to good accuracy of GCT results in previous pregnancy in predicting GDM in index pregnancy. In addition, the NPV of this value is very high, only 7 of 1000 women with this results or lower will have GDM in the index pregnancy (Table). GCT result in previous pregnancy may serve as a screening tool for GDM in an index pregnancy. Parturients with low levels of GCT may not need repeat screening for GDM in the index pregnancy.View Large Image Figure ViewerDownload Hi-res image Download (PPT)