Comparison between postpartum lactate concentration in the umbilical artery and apgar score

ABSTRACT

Postpartum lactate concentration in the umbilical arteries was measured in 237 patients by means of the enzymatic method, using the lactic acid [LA] pack in the Du Pont Automatic Clinical Analyzer. Blood samples were taken immediately postpartum and Apgar scores were determined at one and five minutes, whereby the lactate level in the umbilical artery was found to be higher than the normal adult level [0.6-2.2 mmol/l]. The lowest level was 1.1 mmol/l and the highest was 7.7 mmol/l, with a mean of 3.26 mmol/l, and a standard deviation of 1.36. It was also found that in 184 patients the lactate concentration was less than the mean and only one newborn had an Apgar score of less than 7 at five minutes. In 53 patients, the lactate concentration was more than the mean and 13 newborns had an Apgar score of less than 7 at five minutes. When comparing the frequency of low Apgar scores [less than 7] at five minutes in the two groups [above and below the mean], using the Z-score, there was a statistically significant difference [P < 0.01]. Using the lactate level as a method of assessing the newborn in comparison with the Apgar score, the sensitivity was 92.86% and the specificity was 82.06%