The merit of routine cord blood pH measurement at birth

We searched the literature for mean values of arterial cord blood pH at bir th and their lower limits of statistical normality. An arterial cord blood pH, correctly sampled, measured, validated, and interpreted, provides the m ost objective and sensitive index for fetal hypoxemia during labor. We advi se to sample both artery and vein from a clamped segment of the cord within 30 minutes after birth. In accordance with physiological and statistical e vidence, it is proposed to classify arterial cold blood pH in three categor ies: normal (when > 7.11), abnormal (when < 6.99), and borderline (7.00-7.1 1). An abnormal pH indicates that the fetus was in a state of biochemical d ecompensation at birth. Disadvantages of routine measurement include extra work load and the lack of a universally agreed definition of normal or abno rmal pH. The major advantage of routine measurement is to provide care-give rs with immediate feedback on their care during childbirth and an opportuni ty to learn from that feedback.