1、The amniotic sac breaks and is expelled in the third stage of labor.
在第三產(chǎn)程，羊膜囊破裂并被排出。

2、A protective fluid-filled amniotic sac encloses and cushions the fetus.
充滿液體的羊膜包裹并保護(hù)胎兒緩和震動(dòng)。

3、Fluid in the amniotic sac surrounding the fetus also contains fetal DNA.
羊膜中的液體包圍這胎兒同樣含有胎兒的DNA。

amniotic sac翻譯