[Acid-base balance and umbilical blood gases in neonates born at term in North-Eastern region of Poland].

INTRODUCTION

acidosis observed in infants in the neonatal period can be the cause of many disturbances in adaptation to extra uterine life. In the literature various values of acid-base balance and umbilical blood gases parameters are quoted as borderline between normal and pathological.

AIM

of study was to determine the parameters of acid-base balance and umbilical venous and arterial blood gases in newborn infants from North-Eastern Poland, significant for the evaluation of the condition of the neonate population from this region.

MATERIAL AND METHODS

three groups of newborns were selected for the study. Group I consisted of 492 neonates, born at term, by spontaneous vaginal birth, from single pregnancies, without detectable developmental malformations, without traits of hypotrophy or macrosomy, with normal record of foetal cardiac activity during pregnancy and delivery. Apgar score at 5 min. was >7. Group II consisted of 121 infants born by Caesarean section due to maternal indications. Group III, (75 neonates) was selected from infants born at term by vaginal birth, with Apgar score <or=7 at 5 minutes of life. The material for the study was venous and arterial umbilical cord blood, sampled anaerobically with pre-heparinised sterile syringes. Parameters of acid base balance and blood gases were determined with the use of automated analyser (278 Blood Gases System, Ciba Corning, USA). Quantitative values in the statistical analysis were determined at the level of 2 standard deviations.

RESULTS

statistical analysis showed that abnormal values pO2, HCO3- and BE are below 5 percentile and for pCO2 above 95 percentile. On this basis, the following borderline values for Gp. I are proposed: arterial umbilical blood: pH 7.20, pO2 6.7 mmHg, pC02 62.0 mmHg, HCO3- 19.0 mmol/l and BE -9.7 mmol/l versus venous umbilical blood: pH 7.26, pO2 11.0 mmHg, pCO2 51.5 mmHg, HCO3 17.3 mmol/l and BE -9.5 mmol/l. For group II (elective Caesarean section) there was no statistical significance for the examined parameters. For group III (Apgar <or=7) deterioration of all parameters was observed. There results were statistically significant.

CONCLUSIONS

borderline values for acid-base and blood gas parameters in cord blood of healthy term neonates, delivered vaginally which we have investigated, as well as elaboration of percentile charts for these parameters may be a significant contribution to the evaluation of the status of newborn infants born by spontaneous delivery and by elective Caesarean section.