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，胎盘组织将侵宫层组织，因此不易从宫壁上脱离。

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，即胎盘侵入生长进宫层，无法与宫壁分离。

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.

宫是一器官，被三层平滑所包裹；这平滑也叫作宫层，在分娩过程中收缩，从而缩短宫颈管、扩大宫颈口，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，宫层持续收缩，并将胎盘动脉挤压宫壁上，使动脉被生理结扎，从而减少宫的出血。