v.栓塞；发生栓塞
Amniotic fluid may gain access to uterine veins following a tear in the placental membranes and embolize to the lungs, producing acute dyspnea with cyanosis and shock. 羊水通过羊膜的破裂口进入子宫静脉栓塞到肺，引起急性呼吸困难，伴面色苍白和休克。
