Rapid whole blood lactate measurement in the fetus and mother during labour

Using a new rapid method, fetal and maternal whole blood lactate was measured before the onset of labour at elective Caesarean section in 8 patients, during labour in 34 normal patients, and in a further 28 patients whose babies showed varying degrees of clinical depression and/or acid base abnormality at birth. The mean (+/- SEM) umbilical venous and arterial and maternal venous lactate values in the 8 cases delivered by elective Caesarean section were 1.20 (+/- 0.16), 1.46 (+/- 0.22) and 1.14 (+/- 0.46) mmol/l, respectively. For the normal group the mean fetal lactates (+/- SEM) in the latent and active phases of labour, and in the umbilical vein and artery, were 1.91 (+/- 0.25), 2.42 (+/- 0.46), 2.71 (+/- 0.19) and 3.09 (+/- 0.20) mmol/l, respectively. The mean maternal venous lactate (+/- SEM) in the latent and active phases of labour and at delivery were 1.07 (+/- 0.09), 1.45 (+/- 0.12) and 2.69 (+/- 0.24) mmol/l. the rise in fetal lactate throughout labour was due in part to the rise in maternal lactate. Increasing neonatal depression was associated with increasing fetal lacticacidaemia. This associationachieved statistical significance at delivery.