Fetal Acidosis: Sensitivity and Specificity
Introduction: Intrapartum fetal acidosis, usually secondary to hypoxia, is an indication for immediate delivery of the fetus. Thus, this is the motivation for the current use of continuous fetal heart rate monitoring during labor.
While it is somewhat difficult to actually find the data for sensitivity and specificity of findings on the FHR monitors (many of the studies are from the 70s), I did find the following PPVs from one study. Note that the overall utility of continuous FHR monitoring is at best unclear, and there may be none.
Obstet Gynecol. 1975 Oct;46(4):392-6. PMID: 241036
Beat-to-beat variability was not analyzed in this study.
Am J Obstet Gynecol. 2003 Mar;188(3):820-3. PMID: 12634664
J Matern Fetal Neonatal Med. 2006 May;19(5):289-94 PMID: 16753769