1、产时电子胎儿监护主要内容 胎监应用的历史 应用胎监来筛查产时胎儿缺氧的发展现状 产时缺氧对胎儿及新生儿预后的关系 胎心率与胎儿的生物物理活动的关系 产时缺氧的EFM(Electronic Fetal Monitoring)胎儿监护的发展fetal monitors today have the following features: Reliable, provided they are regularly maintained and serviced User friendly with operating manual and video/DVD FHR recording: by ex
2、ternal Doppler ultrasound (US) with autocorrelation by fetal electrode (ECG) Twin monitoring Maternal heart rate Event marker External tocography Mode, date and time printout Automatic maternal blood pressurepulse and SaO2 facility 胎儿心率的发育 The fetal heart is detectable by transvaginal US as early as
3、 4 weeks after conception At this stage the mean FHR is about 100 bpm. Thereafter it progressively rises, reaching a mean of about 140-150 by 10 weeks menstrual age (8 weeks post conception), and levels off at that rate by the start of the second trimester. From 14 weeks to term there is a progressi
4、ve fall in the mean baseline FHR which is unaffected by whether the fetus is Active or Quiescent This lowering of the baseline rate with gestation is a reflection of the fact that the sympathetic autonomic 胎心率变异胎儿氧供的来源 Fetal oxygenation is therefore dependent upon many factors in this process. Anyth
5、ing that disturbs this chain of oxygen transfer will potentially affect fetal oxygenation and the FHR. The key components of the chain are: Maternal blood pressure and oxygenation The integrity of the placenta, specifically the amount of surface area for oxygen transfer The patency of the umbilical
6、cord 胎心减速 From 26 weeks onwards decelerations of the fetal heart should be regarded as abnormal. However, fetal decelerations are a normal feature before 26 weeks 胎儿产时缺氧 IP fetal hypoxia occurs in about 1% of labours. It can lead to one of three adverse outcomes: Perinatal death (stillbirths and neo
7、natal deaths) Cerebral palsy Hypoxic ischemic encephalopathy (HIE) 胎儿缺氧的机制与结局 Hypoxia may present chronically or acutely. Chronic hypoxia evolves through a series of sequential changes. Acute hypoxia also evolves through a different series of sequential changes. However, both routes eventually can lead to the common outcome判读胎儿电子监护图形的基本要点基线 变异加速 减速宫缩无宫缩-NST有规律宫缩-CST-OCT