胎儿宫内生长迟缓(IUGR),是由于慢性宫内缺氧,使胎儿生长发育落后于正常所致。在临床实践中,产科医生希望胎儿在宫内的时间能维持长一些,长得更大一些,但在等待过程中,有时却发生胎死宫内。因此,寻找一种能预报胎儿安危的方法是十分必要的。目前已有的方法中,产前无应力试验(NST) Fetal intrauterine growth retardation (IUGR), is due to chronic intrauterine hypoxia, so that fetal growth and development lag behind due to normal. In clinical practice, obstetricians hope that the fetus in the womb of time can be maintained longer, grow larger, but in the waiting process, sometimes it happens fetal death. Therefore, to find a way to predict the safety of the fetus is very necessary. Currently available methods, prenatal stress test (NST)