RESUMO
This study aimed to establish the normal range of umbilical artery pH, pCO2, base deficit and lactate in normal term and preterm newborn. Umbilical artery pH, pCO2, base deficit and lactate was measured in 637 newborn babies. The study included 555 babies at term with Apgar score equal to or more than 7 at 5 minutes, not requiring assisted ventilation and not admitted to the neonatal unit (NNU), as well as 47 preterm babies with Apgar score equal to or more than 7 at 5 minutes who were admitted to the NNU for observation only because of prematurity. Data was presented as mean and SD. Statistical analysis was done by t-test and simple linear regression analysis. In the newborn at term mean umbilical artery blood gas and lactate were as follows; pH = 7.25 (+/- 0.08), pCO2 = 45.66 (+/- 1.88) mmHg, base deficit = 7.69 (+/- 3.88) mEq/L, lactate = 2.96 (+/- 1.8) mMol/L. In preterm newborn the values were; pH = 7.25 (+/- 0.04), pCO2 = 51.78 (+/- 13.00) mmHg, base deficit = 5.29 (+/- 1.87) mEq/L, lactate = 2.55 (+/- 1.87) mMol/L. The range of umbilical artery blood gas and lactate parameters in term and preterm fetuses with good neonatal outcome were derived. There was a statistically significant difference in pCO2 and base deficit between term and preterm newborn. There was no linear correlation between lactate, pH, pCO2, base deficit and fetal glucose respectively in term or preterm infants.