Time: An Important Variable at Caesarean Section

Summary Biochemical evidence of fetal asphyxia (relative hypoxia with hypercapnia) and acidaemia has been found in the cord blood of infants delivered by Caesarean section in a series of patients who had been selected to exclude complications of pregnancy which prejudiced the fetal condition before or during anaesthesia. Further, the findings strongly suggest that fetal asphyxia develops progressively, and Apgar scores were lower as the duration of anaesthesia was extended. While changes with time in the general circulation and respiration of the mother could be excluded as the cause of fetal deterioration, local changes in the utero‐placental circulation, due to recumbency or surgical manipulation, and the effect of anaesthetic agents could not.