Gestational Diabetes in Mid-trimester Pregnancy in South Asian Women Based on the Oral Glucose Challenge Test and Risk Factor Predictors: A Prospective Observational Study

Abstract

Introduction: Gestational Diabetes Mellitus (GDM) is a condition potentially occurring during pregnancy. It is associated with adverse foetal and maternal outcomes and is particularly prevalent in South Asian women who comprised this study sample. Aim: To provide a critical analysis of the information on GDM risk that can be identified from screening using the Oral Glucose Challenge Test (OGCT-50 g). Materials and Methods: A prospective cohort study was conducted over eight months. Purposive sampling was used to collect demographic and clinical data {age; Body mass Index (BMI); parity; history of Diabetes Mellitus (DM) in a first degree relative and histories of GDM, polyhydramnious, macrosomia, birth congenital abnormalities and still birth} from 300 South Asian women in mid-trimester pregnancy who consented to undertake an OGCT-50g. Excluded were primigravidas, women with DM or other medical conditions, and women who were unwilling or unable to give informed written consent. Descriptive, comparative and multivariate logistic analyses were used to investigate strengths of correlation between OGCT outcomes and clinical/historical risk factors. Results: The OGCT were 107 (35.7%) positive and 193 (64.3%) negative. The threshold for body mass risk was identified as 27.5 kg/m2. Women with two or more risk factors were OGCT positive on 72.9% occasions whereas women with one or no risk factor were OGCT negative on 81.9% occasions. Approximately, 50% of women had a family history of DM as their only risk factor and 24% of them were OGCT positive. Conclusion: The BMI was the strongest determinant of a positive OGCT result. The logistic regression analysis demonstrated that using the lower BMI threshold of 27.5 compared to 30.0 [as per National Institute for Health and Care Excellence (NICE) guideline] improved agreement between risk factors profile was assessed and OGCT results.