Objective: The aim of this study was to compare the neonatal nucleated red blood cell counts in preterm infants in the presence and absence of clinical and histologic chorioamnionitis while controlling for gestational age and birth weight percentile.
Study design: Nucleated red blood cell counts were obtained from preterm infants delivered after preterm labor or preterm premature rupture of membranes. Patients were divided on the basis of clinical and histologic chorioamnionitis. Nucleated red blood cell counts between groups were compared, and regression analysis controlling for gestational age and birth weight percentile was performed.
Results: Of 359 patients, both measures of infection status were significantly associated with increased nucleated red blood cell counts. In the regression analysis histologic chorioamnionitis retained significance, whereas clinical chorioamnionitis did not.
Conclusions: Histologic chorioamnionitis produces an erythropoietic response in the fetus. Whether fetal erythropoiesis is a direct response to mediators of inflammation or whether it is the result of a rise in erythropoietin is unknown.