Umbilical cord artery blood pH analysis at term pregnancy

Kim, Yeun Hee; Lee, Se Youn; Kwon, Ji Young; Shin, Jong Chul; Park, In Yang

Abstract

OBJECTIVE
To assess the gestational age adjusted values of umbilical cord artery blood pH in term pregnancy
METHODS
We retrospectively analyzed umbilical arterial blood pH values and obstetric data of 1,918 term singleton deliveries without maternal medical disease, pregnancy induced hypertension and fetal distress during labor periods at Kangnam St. Mary's Hospital, Catholic University medical college between January 2004 and December 2006. Low pH was defined as less than 7.10 as a stationary cutoff value, whereas pH less than (mean -2 standard deviations [SDs]) was used when gestational age was considered. We evaluated the risk of 5 minute Apgar score of less than 7 and meconium staining more than grade II at low pH.
RESULTS
A significant negative correlation was found between gestational age and umbilical artery pH (p=0.000). We evaluated the umbilical artery pH value in different delivery mode. Vaginal delivery cases showed negative correlation (p=0.000), but elective cesarean section cases didnt. Low pH patients defined by both criteria of pH less than 7.10 and pH less than (mean -2SD) showed significantly increased risk of 5 minutes Apgar score of less than 7 (pH less than 7.10: p=0. 000, pH less than (mean -2SD): p=0.001) and meconium staining more than grade II (pH less than 7.10: p=0. 001, pH less than (mean -2SD): p=0.001).
CONCLUSION
Our results suggest that umbilical cord pH has a negative relation with gestational age during term period.