胎儿血和氧的供应均来自母体,通过子宫动脉及胎盘循环,经绒毛上皮进行气体交换,再沿胎儿循环将氧输送至胎儿全身各部.上述母胎循环中任何环节有阻断或通而不畅,如绒毛上皮交换功能受损和胎儿心血管系统功能异常,母体血中含氧不足等,均可导致胎儿缺血缺氧.1 缺血缺氧对胎儿影响主要表现在下列三方面1.1 胎儿生长发育.胚胎发育,在妊娠前半期以细胞分裂为主,而在妊娠后半期则以细胞倍增为主,胎儿体重之增长主要在妊娠后半期.因此,采用临床及超声检测法来监护胎儿生长发育,主要应用于妊娠中晚期.目前国内外已将产前常规超声监护胎儿2～3次列 Fetal blood and oxygen supply from the mother through the uterine artery and placental circulation, the villous epithelium for gas exchange, and then along the fetal loop oxygen delivery to all parts of the fetus of the fetus cycle in any part of the block or pass through the poor , Such as villus epithelium dysfunction and fetal cardiovascular system dysfunction, lack of oxygen in the maternal blood, can lead to fetal ischemia and hypoxia.1 The impact of ischemia and hypoxia on the fetus mainly in the following three aspects 1.1 Fetal growth Development. Embryonic development, mainly in the first half of pregnancy cell division, and in the second half of pregnancy to cell doubling, fetal weight increase mainly in the second trimester. Therefore, the use of clinical and ultrasound to monitor fetal growth and development , Mainly used in late pregnancy .At present, both at home and abroad have been prenatal ultrasound fetal care 2 to 3 times