Jeanty P, Renoy P, Van Kerkem J, Dagnelie J, Struyven J
J Ultrasound Med. 1982 Aug;1(6):243-7. doi: 10.7863/jum.1982.1.6.243.
The amnion can be visualized in most pregnancies before the 12th week. It appears as a thin membrane separating the amniotic cavity, which contains the fetus, from the extra-embryonic coelom and the secondary yolk sac. In a prospective study of 32 women in the first 12 weeks of pregnancy, the amnion was demonstrated ultrasonographically in 27 (84 per cent). The embryonic origin of the amnion and possible difficulties in its demonstration by ultrasound are described.
在妊娠12周前的大多数孕妇中，羊膜可被可视化。它表现为一层薄膜，将含有胎儿的羊膜腔与胚外体腔和次级卵黄囊分隔开。在一项对32名妊娠前12周妇女的前瞻性研究中，27名（84%）通过超声显示出了羊膜。本文描述了羊膜的胚胎起源以及通过超声显示羊膜可能存在的困难。
