Fetal transcutaneous carbon dioxide tension during the second stage of labour

Summary. Fifteen women were studied during the second stage of labour by measuring simultaneously fetal transcutaneous carbon dioxide tension (Tc Pco₂ and maternal end-expiratory Pco₂ . A linear increase of Tc Pco₂ with time was observed, predominantly because of changing maternal respiration patterns. The degree of maternal hyperventilation had no adverse effect on the status of the newborn infant.