这是一种最常用的产前诊断手段,尤其是近年来采用了先进的B型超声波扫描仪,使诊断水平有了很大提高。它的优点是无痛苦、快速(半小时以内),可以反复检查等。对于明显的肢体畸形、无脑儿、胎儿内脏畸形、胚胎发育异常、小头畸形、多胎妊娠,以及羊膜腔穿刺时的定位,具有很高的诊断价值。 This is one of the most commonly used methods of prenatal diagnosis, especially in recent years using advanced B-mode ultrasound scanner, the diagnostic level has been greatly improved. Its advantage is no pain, fast (within half an hour), you can check repeatedly. For obvious physical deformity, no brain children, fetal visceral malformations, embryonic development, microcephaly, multiple pregnancy, and amniocentesis positioning, has a high diagnostic value.