Umbilical cord blood pH and Apgar scores as an index of neonatal health.

In an effort to determine the clinical usefulness of Apgar scoring and cord pH in neonatal management, specimens of umbilical cord blood were obtained after 257 of 329 consecutive deliveries at a community-based hospital. A notable number of babies who were born in a vigorous state were in fact acidotic (umbilical arterial pH greater than 1 SD below mean). Seventy-two percent of acidotic babies had an Apgar score greater than 7 at 1 minute, and 92% had an Apgar score greater than 7 at 5 minutes. Correlation coefficients of Apgar scores at 1 and 5 minutes and arterial pH with the health status of newborn infants were poor. A chi 2 analysis of arterial pH and Apgar scores at 1 and 5 minutes indicated that a larger number of sick babies had an Apgar score less than 7 and acidosis than expected by pure chance. However, the sensitivity values of the Apgar score at 1 minute (0.48) and 5 minutes (0.24) and the arterial pH (0.40) for predicting sick children limit the clinical usefulness of these tests. While technically feasible in a community hospital, routine cord pH measurements add little to neonatal evaluation and management.