Some physical and biochemical parameters during normal labour.

A statistical study of parameters of uterine contraction, fetal heart rate, acid-base balance and glycaemia has been made in 30 patients during spontaneous and clinically normal labour for each 2 cm of cervical dilatation. The study of uterine contractility gives the mean values and 95% limits of parameters of uterine contraction as labour progresses. The fetal heart rate is stable during dilation, on the other hand, during the expulsive phase, alterations of fetal heart rate appear, modifications which give evidence of trial that expulsive phase is for the fetus. The study of fetal and maternal acid-base balance shows little change during cervical dilatation, changes towards acidosis during expulsive phase, as importance of feto-maternal relationships. These relationships meet again on the study of glycaemia.