[Lactate measurement in umbilical cord blood in neonates]

In theory, lactate may be used as a more precise measure of the degree of metabolic acidosis than other previous methods, thereby enabling differentiation between acute and chronic foetal hypoxia. The aim of the study was to describe lactate in arterial and venous cord blood in an unselected population of newborn children without signs of foetal hypoxia or perinatal asphyxia.

The study included 208 newborn children. The umbilical cord of the children was double clamped within 30 seconds and thereafter blood was drawn from an umbilical arterial and venous cord. The inclusion criteria were gestational age above 35 weeks and no signs of foetal hypoxia or perinatal asphyxia.

Out of 208 newborn children, 105 children were excluded in accordance with the above criteria, thus the remaining 103 newborn children were included. We demonstrated that lactate and CO2 in arterial umbilical cord blood was higher than in venous umbilical cord blood; furthermore, that O2 and pH in arterial umbilical cord blood were lower than in venous umbilical cord blood. Regression analysis including the factors lactate and "active second stage of labour" showed that lactate significantly increased the longer the "active second stage of labour" lasted.

A reference interval for lactate in arterial and venous umbilical cord blood should be related to the length of "active second stage of labour". This study demonstrates lactate values in arterial and venous umbilical cord blood in an unselected population of newborn children without signs of foetal hypoxia or perinatal asphyxia stratified on mode of delivery.