Glycosylated Hemoglobin in Early Pregnancy as a Marker to  Predict Gestational Diabetes Mellitus – A Prospective Cohort  Study

Authors

Shashikala K Bhat1 , Jyoti M Bali2 , Shashikiran Umakanth3 , Asha Kamath4 , Sahana Shetty5

Glycosylated hemoglobin, HbA1c, OGTT, GDM prediction

Objective: To study the usefulness of glycosylated hemoglobin in early pregnancy to predict gestational

diabetes mellitus.

Material and Methods: We conducted this prospective hospital-based observational study over 30 months.

After obtaining university ethics committee clearance, glycosylated hemoglobin (HbA1c) test was performed

during the booking visit in the first trimester amongst 284 antenatal women attending our hospital. This was

followed by the universal screening with 75g OGTT for all antenatal women during 24-28weeks. Gestational

diabetes mellitus (GDM) was diagnosed based on International Association of the Diabetes and Pregnancy

Study Groups (IADPSG) criteria, and treatment started accordingly. Sensitivity and specificity for prediction

of GDM using HbA1c were calculated based on the receiver operating characteristic (ROC) curve.

Results: 70 of the 284 antenatal women were diagnosed with GDM based on IADPSG criteria. The area

under the curve for using HbA1c in early pregnancy to predict GDM was 0.712. A cut-off of 5.55 for HbA1c

gave a sensitivity of 55.7% (95% CI 49.9, 61.4), specificity 83.6% (95% CI 79.3, 87.9), positive predictive

value (PPV) of 41.5% (95% CI 35.8, 47.2) and negative predictive value (NPV) of 83.7% (95% CI 79.4,

88.0).

Conclusion: HbA1c in early pregnancy may be a useful marker in prediction of GDM. A cut-off of >5.55%

may warrant an early OGTT for diagnosis and treatment of early-onset GDM.

Shashikala K Bhat1 , Jyoti M Bali2 , Shashikiran Umakanth3 , Asha Kamath4 , Sahana Shetty5

1 Professor and Unit Chief, Department of OBG, Dr. TMA Pai Hospital, Udupi, Melaka Manipal Medical College, Manipal Academy of Higher Education, Manipal, India, 2 Assistant Professor, Department of OBG, 3 Professor and Head, Department of Medicine, Dr. TMA Pai Hospital, Udupi, Melaka Manipal Medical College, Manipal Academy of Higher Education, Manipal, India, 4 Professor & Head, Department of Data Science, Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, INDIA, 5Associate Professor and Head, Department of Endocrinology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India