Postural influence on maternal capillary oxygen and carbon dioxide tension

Abstract
The effect of posture on maternal capillary blood Po2 and Pco2 was studied in pregnant and non-pregnant women. There was a significant decrease of Po2 (mean 13·0 mm. Hg) and significant decrease of Pco2 (mean 2·4 mm. Hg) when pregnant women sat up, but these changes did not occur in the non-pregnant. These findings may be relevant to debate on the optimum posture for labour.