Application of glycated hemoglobin in the perinatal period.

Glycated hemoglobin (HbA1c) is a special fragment formed by the binding of glucose to the C chain or D chain of hemoglobin A and as a result of non-enzymatic catalysis of mature hemoglobin and glucose, which is an indicator used to evaluate the blood glucose control in diabetes mellitus (DM) patients. Recent researches indicated that HbA1c could be applied in gestational diabetes mellitus (GDM) and pregnancy combined DM, and increasing of HbA1c was close associated with adverse outcomes of women with pregnancy combined DM and GDM. HbA1c was reported to have a significant importance in monitoring congenital malformation, abortion, perinatal mortality, preeclampsia, postpartum abnormal glucose metabolism, vascular complications and so on, which could be a test item during the second trimester. Sensitivity of HbA1c in diagnoses of DM is lower than oral glucose tolerance test (OGTT), thus OGTT is still the golden standard of GDM. Emphasis should be put on standardization of detection and threshold of HbA1c and establishment of HbA1c normal ranges of different trimesters, when HbA1c is used to diagnose pregnancy combined DM and GDM, and evaluate effects of treatments.