Role of HbA1c in predicting risk for congenital malformations

Abstract

Aims: Association between conventionally identified hyperglycemias and rates of congenital abnormalities is known; however there is less information about role of HbA1c in determining gestational hyperglycemias and associated risks. This study tried to explore the association between HbA1c in women without known diabetes at first antenatal visit and risk of congenital malformations (CM) among Saudi women living at Al-Madinah Al-Monawarah.

Methods: Eleven hundred and eighty (1180), healthy, first-trimester pregnant Saudi females without known diabetes, were selected from various antenatal care clinics of Al-Madinah Al-Monawarah city. General clinical and biochemical data was collected for this study by researchers at first visit and the time of delivery.

Results: Nearly one fifth (19.6%) of mothers had above normal HbA1c (>5.7) at first visit. Rates of CM had significant positive association with level of HbA1c. Rate of CM among those who had HbA1c in diabetes range, pre-diabetes range or normal range was 27.8%, 9.8% and 3.0%, respectively. The difference was significant between normal and pre-diabetes at the level P=0.000 and between pre-diabetes and diabetes at level P=0.038.

Conclusion: In this study HbA1c is found to be a valuable predictor of risk of congenital malformations. This observation calls for further studies and establishment of policies for care of pregnant mothers having higher than normal HbA1c at first visit.

Keywords: Congenital malformations; Gestational hyperglycemia; HbA1c; Saudi Arabia.