The value of fetal scalp blood lactate and/or pH analyses can only be evaluated in relation to neonatal outcome and not to frequency of interventions

摘要

Sir, We have read the article by Liljestrom et al. (1) with great interest and have a number of comments we would like to make. The main issue with a diagnostic test such as fetal scalp blood sampling should be to prevent birth acidemia, which highlights the importance that the test must not have false-negative results (i.e. a normal test although the fetus suffers from hypoxia). Additionally, the numbers needed to treat, i.e operative interventions, to prevent a depressed newborn should be favorable. In the present retrospective study by Liljestrom et al. (1), there is no detailed information about the women included in the groups compared (single testing with lactate or pH vs. combined testing), nor is there any information on why single or combined testing was chosen. Compared with pH measurements, lactate tests are simpler and more rapid to perform. Could it be that in fetuses with the most severe heart rate abnormalities, 'single' lactate tests might have been preferred, and early and rapid intervention could have prevented birth acidemia? The authors have great concerns about false-positive tests, but hardly discuss the false-negative ones.