In conjunction with Apgar scores and other parameters, umbilical-cord blood gas values are used to assess newborn respiratory status. Paired umbilical-cord gas venous and arterial samples were collected from 200 patients to establish reference ranges for blood gas/hemoximetry parameters. Umbilical-cord samples were collected by double clamping a segment of umbilical cord before the delivery of the placenta. Samples were analyzed in duplicate immediately upon arrival in the laboratory. An Apgar score of 7 at 5 minutes was used as the limiting criteria for an infant with normal respiratory status for inclusion of data in reference range analysis.