Relationship between mathematical characteristics of cardiotocography in electronic fetal monitoring and neonatal acidemia / 中华围产医学杂志

ABSTRACT

Objective To explore the relationship between mathematical characteristics of cardiotocograph in electronic fetal monitoring (EFM) and umbilical blood acidosis,and help to evaluate the clinical significance of indeterminate EFM.Methods A total of 85 vaginal delivery cases (or transfer to caesarean section during labor) hospitalized in Peking University Third Hospital during February 4 to December 5,2011 was enrolled in this retrospective study.EFM monitored 0.5-1 hour before delivery was recorded and the mathematical characteristics as the baseline,deceleration area per unit time (cm2/min),deceleration duration ratio and some other variables of EFM were analyzed.All cases were divided into acidosis (n=12) and non-acidosis group (n=73) based on the umbilical blood gas results.Rank sum test or t-test were used to compare the difference on mathematical characteristics between these two groups.Results The deceleration duration ratio and deceleration area per unit time in acidosis group were 0.56±0.17 and 0.45 cm2/min (0.38-0.79 cm2/min),which were higher than those in non acidosis group [0.42±0.14 and 0.30 cm2/min (0.19-0.40 cm2/min)],the differences were statistically significant (t=2.889,Z=2.587,both P＜0.05).There were no statistically significant differences in the number of mild variable deceleration and severe deceleration per unit time between acidosis group and non acidosis group [(0.44± 0.14)/min vs (0.41±0.13)/min,t=1.318,P＞0.05; 0.033/min (0.016-0.062/min) vs 0.016/min (0.008-0.033/min),Z=-1.596,P＞0.05].Conclusions The deceleration duration ratio and deceleration area per unit time can be used to assist the interpretation of indeterminate EFM.