THE RELATIONSHIP BETWEEN APGAR SCORE AND UMBILICAL ARTERIAL BLOOD-GASVALUES IN NEWBORNS

The data for this report were derived from 61 newborns and their mothe rs. Of the newborns 45.9 percent had one-minute Apgar scores of less t han seven, and 54.1 percent had Apgar scores of seven or greater. The five-minute Apgar score was less than 7 in 6.6 percent of cases. While 23 percent of newborns had pH values of less than 7.20, 77 percent ha d pH of 7.20 or greater. Only 39.3 percent of the 28 newborns with one -minute Apgar score of less than 7 and 75 percent of the four newborns with five minute Apgar scores of less than 7 had pH values less than 7.20. Of 33 newborns, 9.1 percent who had Apgar scores of seven or mor e had pH of less than 7.20. We determined the sensitivity of the one m inute Apgar score in acidemia to he 78 percent, the specifity to be 63 percent, the positive predictive value as 39 percent, and the negativ e predictive value as 90 percent. The one minute score is very poor fo r detecting acidosis when present but is rarely misleading when acidos is is absent. There was a positive correlation between the Apgar score and pH (p < 0.001). The best correlation with umbilical artery pH val ues was observed with base excess (-BE) values (p < 0.001). Severe aci dosis (pH < 7.11) was detected in eight cases, As Delta pH increases, pH, pO(2) and HCO3 decrease and pCO(2) increases. Of 11 infants with D elta pH greater than or equal to 0.20, 63.6 percent were sick infants and only one (9%) had normal Apgar scores.