Predictive value of fetal scalp pH and base excess for fetal acidosis and poor neonatal outcome

AbstractObjective: The objective of this study is to assess retrospectively the predictive value of fetal scalp pH and base excess (BE) for fetal acidosis and poor neonatal outcome in term, low-risk, spontaneous deliveries with suspicious or pathological intrapartum cardiotocography (CTG) tracings.Methods: Umbilical artery pH and BE values obtained immediately after delivery and Apgar score were the outcomes under consideration. Statistics included receiver-operating characteristic curve (ROC) and multiple logistic regression analysis.Results: Four hundred and six deliveries were included in the study. Scalp pH < 7.20 predicted umbilical pH ≤7.1 with 64.3% sensitivity and 92.9% specificity (p < .001). The corresponding positive-predictive value (PPV) was 24.3% and the negative-predictive value (NPV) was 98.6%. Scalp BE ≤ −7 mmol/l (a cut-off value provided by ROC curve analysis) predicted Apgar score ≤ 7 at 5 min with 61.9% sensitivity and 91.7% specificity (p < .001). The corresponding PPV and NPV were 2...