The relationship between umbilical cord blood pH and cardiac findings in neonates admitted to neonatal intensive care unit

Abstract

Background: Determining the umbilical cord blood pH can be used for predicting of different serious damages in neonates. This study aimed to examine the relationship between umbilical cord pH and neonatal cardiac findings.

Methods: In this descriptive cross-sectional study, 600 neonates (52.7% boys and 47.3% girls) who admitted to the NICU of Akbarabadi Hospital were considered. Umbilical cord pH was measured immediately after the birth and the basic demographic and clinical data of newborns were recorded. Echocardiography was performed for all infants and the relationship between umbilical cord pH and echocardiographic findings was assessed.

Results: The mean of umbilical cord pH in male and female neonates was 7.28 and 7.24, respectively (p = 0.004). Decreased gestational age (p = 0.003), birth weight (p <0.001), Apgar scores (p <0.001) and hypotension (p <0.001) were significantly associated with umbilical cord blood acidosis. The mean of umbilical cord pH in single and twin infants was 7.26 and 7.22, respectively (p = 0.026). The mean of umbilical cord pH in neonates without pulmonary support was significantly higher than neonates with pulmonary support (7.34 vs 7.23; p <0.001). Decreased umbilical cord pH was significantly associated with patent ductus arteriosus (p <0.001), mitral regurgitation (p = 0.006) and pulmonary arterial hypertension (p <0.001). A significant trend was observed for lower mean cord blood pH value in newborns with PFO than subjects without PFO (7.25 ± 0.11 vs 7.29 ± 0.06; p=0.003). 

Conclusion: Decreased umbilical cord pH can be considered as an important risk factor for developing heart failures in newborns.