P88Cardiotocography predicting buffer base deficit (> 10 mM) at birth in pregnancies with absent or reversed end‐diastolic velocity in the umbilical artery Doppler studies

Background A study of cardiotocographic (CTG) variables and buffer base deficit at birth in fetuses with AREDV. Methods The last CTGs of 127 AREDV cases were correlated to buffer base deficits above 10 mM. The variables selected by the Logistic Regression model were: baseline, accelerations, variability (variab.), sinusoidal pattern, bradycardia, late and variable (var.) decelerations (mild, moderate and severe). Results The maximum likelihood estimates are shown with the variables:1 Table 1.  Variable Parameter estimate Standard error P Odds ratio Intercept −0.4976 1.8374 0.7865   GA (weeks) −0.0195 0.0590 0.7407 0.981 variab. 5–9 bpm 0.5330 0.4431 0.2290 1.704 Variab. < 5 bpm 2.5275 0.5804 0.0001 12.522 Conclusion The analysis of cardiotocographic variables makes it possible to estimate the probability of a base deficit above 10 mM at birth, i.e. buffer base depletion. Low placental permeability to bicarbonate and buffer base is an advantage for studying these results, which are less influenced by acute events.