Changes in plasma lactate concentration in women in labour and their newborns within the first days of life.

Changes in venous-blood lactate level were studied in women in three periods of labour and three time periods after labour, as well as in their newborns in the umbilical core blood and during the first several days of extrauterine life. The level was highest in women at the time of fetus delivery (passage of fetal head through the genital channel) and in the umbilical cord blood in newborns. The return of normal lactate value occurred parallelly in mothers and newborns. In several cases of labour with complications not induced pharmacologically the lactate levels were not different from those observed during spontaneous labours.