Correlation between Umbilical Cord pH and Apgar Score in High-Risk Pregnancy

The Apgar score as a proven useful tool for rapid assessment of the neonate is often poorly correlated with other indicators of intrapartum neonatal well-being. This study was carried out to determine the correlation between umbilical cord pH and Apgar score in high-risk pregnancies.

This is a prospective cross-sectional, analytic study performed on 96 mother-fetal pairs during 2004-2005 at Shahid Yahyanejad Hospital, which is affiliated to Babol University of Medical Sciences. Apgar score at 1 and 5 minutes after birth was taken and an umbilical cord blood gas analysis was done immediately after birth in both groups. Mothers came with a labor pain and were divided into high-risk and low risk if they have had any perinatal risk factors. Other data like gestational age, birth weight, need for resuscitation and admission to the newborn ward or Neonatal Intensive Care Unit was gathered by a questionnaire for comparison between the two groups. P-value less than 0.05 was considered being significant.

The gestational age and birth weight were the same in high-risk and low risk mothers. Mean umbilical artery blood pH in high-risk mothers was significantly lower than in low risk mothers (P=0.004). Mean Apgar scores at 1 and 5 minutes were significantly lower in high-risk mothers than in low risk mothers (P<0.05). According to the Kendal correlation coefficient there was no significant correlation between Apgar score at 1 and 5 minutes and umbilical cord pH in low risk group (r=0.212, P=0.1). But in high-risk group there was significant correlation between Apgar score at 1(st) and 5(th) minute and the umbilical cord pH (r=0.01, P=0.036 and r=0.176, P=0.146, respectively).

Combination of Apgar score and umbilical cord pH measurement in high-risk pregnant mother could better detect jeopardized baby.