Outcomes among term infants when two-hour postnatal pH is compared with pH at delivery

Objective: This study was undertaken to measure infant outcomes when pH at birth was compared with neonatal pH determined within 2 hours of age. Study Design: We retrospectively studied term infants born between January 1, 1988, and August 31, 1998, who had umbilical artery blood pH measured at birth and again from the radial artery or umbilical artery within 2 hours after birth. Statistical significance was determined with the χ2 test. Odds ratios and 95% confidence intervals were calculated by means of the Mantel-Haenszel method. Results: Data from a total of 1691 infants were analyzed: 178 (11%) had acidemia at birth (pH of