胎儿脑电图及其定量分析用于产时胎儿窘迫诊断的研究

Dignosis of fetal distress by fetal electroencephalogram and fetal quantitative electroencephalogram

目的探讨胎儿脑电图(fetal electroencephalogram,FEEG)波形及其定量分析用于产时诊断胎儿窘迫及判断新生儿预后的价值。方法采用自制的经阴道胎儿脑电电极对65例产妇在第一产程末至胎儿娩出前进行FEEG监测,观察脑电图波形变化并进行定量分析;并将胎儿窘迫组(22例)和非胎儿窘迫组(43例)的脑电图波形及定量分析结果进行比较。同时比较胎儿酸中毒组和血气正常组两组的脑电图波形,分析新生儿近期预后与产时FEEG关系。结果(1)应用经阴道直接接触胎儿头皮的脑电电极记录的脑电图与新生儿脑电图特点相似;(2)胎儿窘迫组产时脑电图波形异常率明显高于非胎儿窘迫组(72·7%和9·0%,P<0·05),前者双频指数(bispectral index,BIS)明显降低、95%边缘频率(spectral edge frequency,SEF)明显升高;(3)胎儿酸中毒组与血气正常组相比产时脑电图及其定量分析有显著异常(BIS:48·23±1·98和70·18±0·76,P<0·05;95%SEF:29·02±1·09和14·02±1·69,P<0·01);(4)产时FEEG异常与新生儿不良预后有关。结论(1)自制的经阴道胎儿脑电电极可准确地采集胎儿脑电信号,且不损伤胎儿头皮,是安全、可行的;(2)胎儿脑电波异常可较早的反映胎儿宫内缺氧及酸中毒的状况,并可做为产时胎儿监测的直观指标;(3)产时胎儿脑电图定量分析BIS、95%SEF是反映胎儿和新生儿缺氧及酸中毒的敏感指标。

Objective To investigate the value of fetus electroencephalogram （FEEG） monitors during labor in diagnosing intrauterine fetal hypoxia and predicting the outcomes of newborns. Methods FEEG monitoring was conducted in 65 gravidas of full term pregnancy during labor using self-made electrodes and the patterns and quantitative analysis of FEEG waves were performed. The results were compared between the normal pregnant group and the fetal distress group. The wave patterns were also compared between those fetus with and without acidosis determined with the umbilical cord artery blood. The relationship between FEEG and the short-term outcomes of the newborns were also analyzed. Results The characteristics of FEEG during labor by self-made electrodes was the same as that of newborn EEG. The abnormal FEEG rate in the distress group was significantly higher than that of the non-distress group （72.7% vs 9.0%, P〈0.05） with lower bispectral index, （BIS） and elevated 95% （spectral edge frequency, SEF）. The quantitative analysis of the FEEG showed significant abnormalities in the acidosis group than the normal blood gas group （BIS： 48. 234±1.98 vs 70.18±0.76,P〈0.05;95% SEF：29. 02±1. 09 vs 14.02±1.69, P〈0.01）. Abnormal FEEG was correlated with adverse neonatal outcomes. Conclusions The self-made fetal electrodes for vaginal FEEG is safe and feasible without any harm to the fetal scalp. Abnormal FEEG implies fetal hypoxia or acidosis earlier, thus makes it a visible method for fetal surveillance during labor. The quantitative EEG index such as BIS and 95% SEF are sensitive indicators in detecting fetal or neonatal acidosis. FEEG monitoring during labor can predict the short-term outcomes of the neonates.