胎儿遗传性疾病的诊断已成为产科监护的组成部份,然而经腹部羊膜穿刺对孕龄的增长以及以后准备羊水细胞培养的时间很不利,因此医生和病人在探索较早的诊断方法。另一种方法是经宫颈取绒毛标本,此法较羊膜穿刺得到的胎儿细胞成功率稍低,而有时胎儿流产率稍高,另外用这种方法确诊多胎妊娠经常不可靠。1989年Evans等报道经腹部早期羊膜腔穿刺的方法,在穿入子宫必须经过充盈的膀胱可能遇到困难,因此在操作期间的实时超声观察受限制。在早期妊娠试图避免上述任何一种产前诊断有 Diagnosis of fetal genetic disease has become an integral part of obstetric care. However, transabdominal amniocentesis is a time-consuming measure of gestational age and subsequent preparation of amniotic fluid cells, so doctors and patients are exploring earlier diagnostic methods. The other method is cervical transcervical specimens, this method than amniocentesis fetal cells obtained slightly lower success rate, and sometimes higher rates of fetal miscarriage, in addition to using this method to confirm multiple pregnancy is often not reliable. In 1989, Evans et al. Reported that early transabdominal amniocentesis may be difficult to penetrate the filling bladder when penetrating the uterus. Therefore, real-time ultrasound observations during operation are limited. Trying to avoid any of these prenatal diagnoses in early pregnancy