Neonatal Polycythemia in Infants of Gestational Diabetic Mothers

Abstract

Background & Objectives: Neonatal polycythemia (venous hematocrit 65%) is a well-recognized hematological complication in infants of gestational diabetic mothers (IGDMs). Fetal hyperinsulinemia and intrauterine hypoxia accelerate erythropoiesis, leading to increased red cell mass and blood hyperviscosity. This prospective observational study evaluated the incidence, hematological parameters, risk factors, and immediate clinical correlates of neonatal polycythemia in IGDMs admitted to the Neonatal Intensive Care Unit (NICU). Methods: A hospital-based prospective cohort study was conducted in the NICUs attached to J.J.M. Medical College (Bapuji Child Health Institute, C.G. Hospital, and Women and Children Hospital, Davangere) over an 18-month period. A total of 105 live-born neonates of mothers with gestational diabetes mellitus (GDM) were enrolled. Central venous hematocrit was measured between 2 and 4 hours of life via microhematocrit centrifugation. Polycythemia was defined as a venous hematocrit 65%. Hematological parameters, timing of maternal GDM onset (early <24 weeks vs. late > 24 weeks), birth weight percentiles, and associated metabolic conditions were evaluated. Results: The overall incidence of neonatal polycythemia was 27.6% (n=29/105). Polycythemia occurred in 30.0% (n=6/20) of infants born to mothers with early-onset GDM and in 27.1% (n=23/85) of those born to mothers with late-onset GDM. Large for gestational age (LGA) infants demonstrated a higher rate of polycythemia compared to appropriate for gestational age (AGA) infants. Polycythemic neonates showed a strong co-occurrence with hyperbilirubinemia (43.8% overall incidence) and hypoglycemia (64.8% overall incidence). Conclusion: Neonatal polycythemia is a frequent hematological alteration in IGDMs, affecting over a quarter of live births. Mandatory venous hematocrit screening at 2 to 4 hours of life is essential in all IGDMs to facilitate early detection and prevent hyperviscosity-related microvascular complications.