Characteristics of different risk factors and fasting plasma glucose for identifying GDM when using IADPSG criteria: a cross-sectional study

Abstract

BackgroundThe Swedish National Board of Health and Welfare (SNBHW) recommended the new diagnostic criteria for GDM based upon Hyperglycaemia and Adverse Pregnancy Outcomes (HAPO) study thresholds. Due to limited knowledge base, no recommendations were made on GDM screening. The aim of this study is to evaluate test characteristics of risk factors and fasting blood glucose as screening tests for diagnosing GDM using diagnostic thresholds based upon HAPO study 1.75/2.0 (model I/II respectively) odds ratio for adverse pregnancy outcomes.MethodsThis cross-sectional, population-based study included all pregnant women who attended maternal health care in Örebro County, Sweden between the years 1994–96. A 75 g OGTT with capillary fasting and 2-h blood glucose was offered to all pregnant women at week 28–32. Risk factors and repeated random glucose samples were collected. Sensitivity, specificity and predictive values of blood glucose were calculated.ResultsPrevalence of GDM was 11.7% with model I and 7.2% with the model II criteria. Risk factors showed 28%, (95% CI 24–32) and 31%, (95% CI 25–37) sensitivity for model I and II respectively. A fasting cut off ≥4.8 mmol/l occurred in 24% of women with 91%, (95% CI 88–94) sensitivity and 85%, (95% CI 83–86) specificity using model I while a fasting cut off ≥5.0 mmol/l occurred in 14% with 91%, (95% CI 87–94) sensitivity and 92%, (95% CI 91–93) specificity using model II.ConclusionRisk factor screening for GDM was found to be poorly predictive of GDM but fasting glucose of 4.8–5.0 mmol/l showed good test characteristics irrespective of diagnostic model and results in a low rate of OGTTs.

Gestational Diabetes: Comparison of Random and Fasting Plasma Glucose as Modalities of Screening

“…Although both studies were performed in pregnant individuals, Agbozo et al 25 screened subjects using a universal approach when compared to the selective screening based on risk factors that was used in this study. This could have accounted for the higher specificity found in this study; however, the finding was higher than the positive-predictive value found in a study by Saeedi et al, 26 which gave positive-predictive value of 78% at FPG threshold of 5.2 mmol/L. However, Saeedi et al 26 screened a population of pregnant females with known risk factors for gestational diabetes and the study was carried out in Swedish population.…”

“…This could have accounted for the higher specificity found in this study; however, the finding was higher than the positive-predictive value found in a study by Saeedi et al, 26 which gave positive-predictive value of 78% at FPG threshold of 5.2 mmol/L. However, Saeedi et al 26 screened a population of pregnant females with known risk factors for gestational diabetes and the study was carried out in Swedish population. Geographical variation in risk factors may be possible explanations for these differences observed.…”

Risk Factors Screening for Gestational Diabetes Mellitus Heterogeneity in Chinese Pregnant Women: A Case–Control Study

“…40,41 Many studies considered the increasing level and cutoff points of FBS in early pregnancy as a risk factor for GDM, but their results are inconsistent. [42][43][44] The areas and ethnic variations among participants, and the different diagnostic criteria for GDM may explain the reasons for these inconsistencies. In this study, the association between the elevated level of FBG in the first trimester and GDM might be relevant to the high-carbohydrate diet of women in the northwest of China.…”

An Update on Screening Strategies for Gestational Diabetes Mellitus: A Narrative Review

“…90 Likewise, a retrospective study found that risk factor screening for GDM alone or in combination with random capillary glucose was poorly predictive of GDM, but FPG 4.8-5.0 mmol/l showed good test characteristics and resulted in a low rate of OGTTs needed. 91 A study evaluating FPG as a screening tool to rule-out GDM in a lowrisk population found that women with FPG ≤3.4 mmol/L were at low risk of developing GDM with a sensitivity of 91.3%, thereby avoiding a two-step screening in 10% of their population. 92 Some authors suggest that sensitivity and specificity for risk-factor based GDM screening could be considerably improved by using clinical risk prediction models that include combinations of several risk indicators in combination with FPG for improved prediction.…”

“… 90 Likewise, a retrospective study found that risk factor screening for GDM alone or in combination with random capillary glucose was poorly predictive of GDM, but FPG 4.8–5.0 mmol/l showed good test characteristics and resulted in a low rate of OGTTs needed. 91 A study evaluating FPG as a screening tool to rule-out GDM in a low-risk population found that women with FPG ≤3.4 mmol/L were at low risk of developing GDM with a sensitivity of 91.3%, thereby avoiding a two-step screening in 10% of their population. 92 …”