ABSTRACT
The study comprised 300 term nulliparous women with spontaneous onset of labour and with no medical or surgical disorders. Umbilical artery pH and blood gases were measured immediately after labour and evaluated in relation to 5 minute Apgar score to assess the importance of obtaining cord blood gas levels in all deliveries. Acidemic newborns [pH < 7.2] had highly significant increase in the C02 tension [P Col] and highly significant decrease in standard base concentration [SBE] and O2 saturation [SAT]. The incidence of depressed newborns [Apgar score < 7] was 16.3% among them the incidence of normal umbilical cord arterial pH was 83.7%, while of the vigorous newborns [Apgar score > 7], there was 2.3% incidence of cord arterial blood acidemia. There was highly significant increase in the frequency of newborns with abnormal pH and SAT values among the depressed newborns in comparison with vigorous newborns. Thus our study suggests that cord arterial pH value is extremely useful in railing out the diagnosis of birth asphyxia in 83.7% of the depressed newborns as well as providing objective documentation of normal acid base balance in 97.7% of the vigorous newborns. Also, cord arterial SAT values has significant correlation with pH and Apgar score, a finding suggesting further evaluation