Effect of anemia and erythrocyte indices on hemoglobin A1c levels among pregnant women.

Background: Anemia is a common disorder among pregnant women; however, the effect of anemia on hemoglobin A1c (HbA1c) levels has not been adequately explored. We aim to examine the influence of anemia on the HbA1c concentration and investigate the relationship between erythrocyte indices and HbA1c levels during pregnancy.

Methods: We performed a retrospective analysis of 1369 pregnant Chinese women. The clinical and analytical data were collected. Independent t-test and Analysis of Variance were used for comparative studies, and multiple linear regression analysis was used to identify the association between erythrocyte indices and HbA1c.

Results: The differences in HbA1c between non-anemia and mild anemia were negligible, and the differences in HbA1c between non-anemia and moderate anemia were well within the allowable variability for clinical practice (≥0.5% absolute changes). Mean corpuscular hemoglobin (MCH) correlated with HbA1c significantly, independent of pregnancy, trimester, and anemia. The distinction of HbA1c levels between grades of Hb became no significant (P = 0.955), while differences between trimesters persisted after adjusting for MCH.

Conclusion: Mild and moderate anemia should not be the primary concern when using HbA1c to monitor blood glucose in pregnancy. MCH showed negative correlations with HbA1c independently, suggesting a previously unknown mechanism affecting HbA1c levels.