Lactate in fetal scalp blood and umbilical artery blood measured during normal labor with a test strip method

A new test strip method was used to determine the lactate concentration in fetal scalp blood during normal labor. Sixty-six fetal scalp blood samples were collected at cervical dilatations between 4 cm and 10 cm. The mean lactate value was 1.7 +/- 0.8 mmol/l simultaneously (IS.D.) and the mean pH sampled simultaneously was 7.36 +/- 0.04 (IS.D.). The corresponding values for base deficit was 2.1 (+/- 1.9) and for pCO2 5.8 (+/- 0.8). No difference was seen in lactate concentrations or pH values in early compared to late first stage of labor. The mean lactate concentration in the umbilical artery immediately after delivery was 3.7 mmol/l +/- 1.2 (IS.D.). The method was easy to handle and gave the result within 60 seconds.