Neonatal organ dysfunction among newborns at gestational age 34 weeks and umbilical arterial pH<7.00.

PURPOSE: Among newborns at 34 weeks or more with umbilical arterial pH<7.00, we endeavoured to determine the pH threshold and risk factors for neonatal organ injury within 72 hours of birth.

STUDY

DESIGN

Retrospectively, all non-anomalous newborns delivered over 6 years near term with a low pH were identified. Each case of a newborn with injury was compared with the next four neonates with a pH below 7.00 and no injury. A receiver-operating characteristic (ROC) curve and unconditional logistic regression was used.

RESULTS

Of the 87 newborns with pathologic acidosis, 16% had neonatal organ system injury. Inspection of the ROC curve indicates that a pH of 6.92 is the threshold that identifies newborns who will have damage to organs. Unconditional logistic regression analysis indicates that the significant risk factors for morbidity were an Apgar score <or=7 at 5 minutes, an UA pH <or=6.92, a sentinel event, and a history of maternal seizures among those at 37 weeks or more.

CONCLUSIONS

Among newborns at >or=37 weeks, pH <or=6.92 is the threshold linked with neonatal organ dysfunction.