Nucleated red blood cells in meconium aspiration syndrome

Objective: To evaluate whether the absolute nucleated red blood cell (RBC) count is higher in infants who had meconium aspiration with respiratory symptoms compared with infants with asymptomatic meconium aspiration and controls. Methods: We compared the absolute nucleated RBC counts during the first 12 hours of life in three groups of term, vaginally delivered infants, including those who had meconium aspiration with respiratory symptoms (n = 11), asymptomatic meconium aspiration (n = 45), and control healthy infants (n = 32). We excluded infants of women with diabetes in pregnancy; hypertension; alcohol, tobacco, or drug abuse; and those with hemolysis, blood loss, or chromosomal anomalies. Results: There were no significant differences among groups in gestational age; gravidity; parity; maternal analgesia; lymphocyte, platelet, and granulocyte counts; and hematocrit. The median nucleated RBC count was significantly higher in the meconium aspiration group with respiratory symptoms (0.007 × 10⁹/L) than the asymptomatic meconium aspiration group (0.004 × 10⁹/L) or controls (0.003 × 10⁹/L). Conclusion: At birth, infants with meconium aspiration syndrome had higher absolute nucleated RBC counts compared with infants with asymptomatic meconium aspiration and normal infants.