Utility of Early Pregnancy HbA1C in detecting Gestational Diabetes Mellitus among High-Risk Women in Nigeria

Abstract

ABSTRACT

Background: Gestational Diabetes Mellitus GDM is a major cause of maternal and perinatal morbidity and mortality. Early detection and treatment will ensure good pregnancy outcomes. There is a paucity of data regarding the use of HbA1c in classifying and managing hyperglycaemia in pregnancy in Nigeria. This study set out to investigate the utility of early pregnancy HbA1c values in detecting hyperglycaemia among Nigerian pregnant women.

Materials and Methods

A total of 125 pregnant women presenting for their booking visits at 20 weeks or less of gestation and having one or more risk factors for GDM were recruited and blood samples were taken for HbA1c and OGTT determination according to the WHO protocol.

Results

The mean (SD) age of the study population was 30.4 (5.8) years. The prevalence of HIP from this study after screening at early gestation (<20 weeks) was 15.2% of which 13.3% was classified as GDM. There was a significant correlation between HBA1c and 0-hour glucose (r=0.412), 1-hour glucose (r=0.394), and 2-hour glucose (r= 0.379), P<0.001. At HbA1c of 5.4% and 5.7%, the sensitivity for detecting HIP was 66.7% and 22.2% respectively and the specificity was 65.9% and 80.5% respectively. At HbA1c of 5.4% and 5.7%, the PPV was 26% and 16.9% respectively while the NPV was 88.2% and 79.7% respectively.

Conclusion: The study shows a very high prevalence of HIP in early pregnancy among women with a high risk for GDM. HbA1c correlated moderately well with glucose levels in early pregnancy. Overall, HbA1c does not have a very robust sensitivity and specificity for diagnosis of HIP when used alone. However, the utility appears to be better when used as a marker to rule out HIP in early pregnancy.