ABSTRACT
OBJECTIVE: To determine whether meconium staining can be the indicator of intrauterine hypoxia by comparing umbilical venous erythropoietin (EPO) concentration and the number of nucleated erythrocytes (NRBC), as a marker of intrauterine hypoxia, between non meconium-stained neonates and meconium-stained neonates of term pregnancy. And to determine correlation between the number of NRBC, EPO levels and interleukin-6 (IL-6), as another mediator of intrauterine hypoxia. METHODS: In 240 neonates with gestational age ranged from 37 to 41 weeks, including 231 cases of nonmeconium-stained neonates and 9 cases of meconium-stained neonates, we performed the measurement of EPO levels by RIA, the number of NRBC per 100 white blood cells (WBC) by blood smear and IL-6 by ELISA in umbilical venous blood at delivery. Statistical analysis was performed by chi-square test, Wilcoxon rank sum test, linear regression analysis using SPSS 11.0 version statistical package. RESULTS: Amniotic fluids of meconium-stained neonates had significantly greater EPO concentrations compared with that of nonmeconium-stained controls (41.3+/-13.0 vs 26.5+/-18.9 mIU/mL, p=0.001). But there were no statistical difference in the number of NRBC, IL-6 levels and hematocrit of umbilical venous blood. The EPO levels in umbilical venous blood was correlated with the number of nucleated erythrocytes (r2=7.7%, p<0.001), and IL-6 in umbilical venous blood was correlated with the number of NRBC. (r2=11.5%, p<0.001). CONCLUSION: These results suggest that meconium-stained amniotic fluid can be associated with fetal hypoxia. And the production of fetal NRBC is thought to be stimulated by EPO and IL-6, but it requires further study of other (yet to be determined) hypoxia-derived mediators.