Relationship between Decelerations with Late Components in the Second Stage ofLabor and Umbilical Cord Artery PH

摘要

This study explored the relationship between decelerations with late componentsin the second stage of labor and umbilical cord artery pH at birth. Physiologic theories state that late decelerations reflect fetal stress and potentially compromised fetal oxygenation. A retrospective study of 30 births was conducted. The subjects selected were the first 30 fetal monitoring tracings meeting research criteria of over 300 reviewed at a mid-western military medical center. For each subject, the researcher recorded all decelerations with late components. The mean length of the late component, mean length of the deceleration, and the percent of contractions involved with these decelerations was calculated for each subject. The subjects were then sorted into two groups based on the pH of the umbilical cord artery at birth, pH <7.2 and pH = or > 7.2. Five of the 30 were in the low pH group. The two groups were demographically similar. The data were analyzed using correlation and t-tests. Weak negative correlations were found between the mean length of the late component, mean length of the deceleration, percent of contractions involved, and the pH. When the two groups were compared, the lower pH group had significantly longer decelerations and a higher percentage of contractions involved with decelerations. Also, no subject in the low pH group had a mean late component length of less than 60 seconds. The investigator concluded that the findings identify a need for further research to verify the relationships found.