Role of Altered Venous Blood Lactate and HbA1c in Women with Gestational Diabetes Mellitus.

Introduction: Being a mirror image of metabolic syndrome, Gestational Diabetes Mellitus (GDM) is associated with significant maternal and fetal morbidity. Increased blood lactate concentration and alterations of substrate utilization are partly involved in development of insulin resistance in GDM. Fetuses born to such mothers have shown low umbilical vein oxygen saturation and low oxygen content and increased lactate concentrations. These changes may certainly reflect enhanced fetal metabolism as a result of hyperglycaemia and hyperinsulinemia and therefore, these fetuses deserve intense surveillance at term and during delivery. Ideally, HbA1c should be maintained below 5% during their first trimesters and below 6% during third trimester. We planned to investigate GDM women for their HbA1c levels too.

Aim: To know if there is any alteration in blood lactate and/or HbA1c levels and to know if there is any correlation between these two parameters in GDM pregnancies, in comparison with the previous studies which measured lactate in cord blood and placental vessels of GDM women.

Materials And Methods: It was a hospital based prospective study on 40 women with gestational diabetes and 40 age-matched normal pregnant women. We analysed the biochemical and metabolic mileau in these women by estimating venous blood lactate and HbA1c levels. We paid special attention to follow them up regarding maternal complications if any and perinatal outcomes. The independent samples t-test and Pearson's correlation test were applied.

Results: GDM mothers showed significantly higher lactate and HbA1c levels than normal pregnant women, both with p<0.001. Blood pressure and fetal birth weight were also significantly higher in GDM group than Normal Pregnant (NP) group, both with p-values of <0.001. Further, this increased lactate levels showed significant positive correlation with HbA1c, blood pressure and fetal birth weight.

Conclusion: Maternal blood lactate and HbA1c levels have a significant role to play in determining the metabolic mileau of both mother and fetus and thus, their obstetric and general health outcomes.