Collecting and Analyzing Cord Blood Gases

The analysis of cord blood respiratory gases and acid-base values is an important adjunct for determining the extent and cause of fetal acidosis at delivery. Although the quality and reliability of the blood gas instruments have improved dramatically, constant vigilance still is required and mandated to ensure accurate and precise results. Failure to control the many sampling and analysis variables that affect cord blood gas results will limit their usefulness. Most preanalytic problems become a minor concern when the blood gas analyses are done within a few minutes after obtaining the sample. Comparison of data among centers requires, not only that reference ranges be stated, but also that various corrections or factors that were used to adjust the results be described. Perhaps, a consensus could be reached to establish the optimal method of collection and the best methods for analyzing and reporting the results from cord blood gas and acid-base studies.