The Role of Glycemic Biomarkers in the Third Trimester of Pregnancy for Improving Pregnancy Outcomes

Abstract

Background: Gestational diabetes mellitus (GDM) is a common pregnancy disorder associated with adverse maternal and neonatal outcomes. During the third trimester, increased insulin resistance and rapid fetal growth require accurate glycemic monitoring. However, conventional markers like RBS and HbA1c have limitations, making short-term markers such as fructosamine, albumin-corrected fructosamine (ACF), and fructosamine–albumin ratio (FAR) useful alternatives for predicting outcomes.

Aim: To review the role of glycemic biomarkers in the third trimester of pregnancy and evaluate their usefulness in predicting adverse pregnancy outcomes in women with gestational diabetes mellitus.

Materials and Methods: A narrative review was conducted using published studies retrieved from electronic databases and relevant reference sources regarding glycemic biomarkers in gestational diabetes mellitus. Studies evaluating RBS, HbA1c, fructosamine, serum albumin, albumin-corrected fructosamine, and fructosamine-albumin ratio during the third trimester and their association with maternal and neonatal outcomes were reviewed.

Results: RBS provides only an immediate estimate of glycemia and has limited value in assessing overall glycemic control. HbA1c reflects long-term glycemic status over 8–12 weeks but may underestimate hyperglycemia during late pregnancy due to increased erythrocyte turnover, anemia, and hemodilution. Fructosamine reflects short-term glycemic control over 2–3 weeks but is influenced by serum albumin concentration. ACF and FAR minimize the effect of hypoalbuminemia and demonstrate a stronger association with adverse pregnancy outcomes, including fetal macrosomia, large-for-gestational-age infants, preterm birth, neonatal hypoglycemia, hypertensive disorders, and increased cesarean delivery.

Conclusion: Fructosamine-based biomarkers, especially ACF and FAR, appear to be superior to conventional markers for evaluating glycemic control during the third trimester. Their use may improve the prediction of adverse pregnancy outcomes and optimize the management of gestational diabetes mellitus.