In placenta accreta, the placenta invades the myometrium so it doesn't easily separate from the uterus.

当发生胎盘植入时，胎盘组织将侵袭到肌层组织，因此不上脱离。

Placenta previa is also associated with placenta accreta, which is where the placenta invades the myometrium and becomes inseparable from the uterine wall.

前置胎盘有时伴有胎盘生，即胎盘侵入性生长进肌层，无法与分离。

The uterus is a muscular organ wrapped by three layers of smooth muscle called the myometrium, which contracts during labor to dilate and efface the cervix and ultimately push out the fetus and placenta.

是一种肌性器官，被三层平滑肌所包裹；这种平滑肌也叫作肌层，在分娩过程中收缩，而缩短颈管、扩大颈口，最终将胎儿和胎盘娩出体外。

After delivery, the myometrium continues to contract and this squeezes down on the placental arteries at the point where they are attached to the uterine wall, clamping them shut, thereby reducing uterine bleeding.

在分娩之后，肌层持续收缩，并将胎盘动脉挤压到上，使动脉被生理性结扎，而减少的出血。