Power refers to forceful uterine contractions, passenger refers to the fetus, and passage refers to the route that the fetus has to travel through the bony pelvis.

产力指有力的子宫收缩，出物指胎儿，产道指胎儿穿过骨盆的路径。

Yes, so labor is the physiologic process of delivery of a baby from the uterus, through the cervix, through the vagina, and it requires regular uterine contractions, dilation of the cervix, and thinning of the cervix, or effacement.

的，指通过子宫、宫颈和阴道将婴儿出的理过程，这一过程要有规律的子宫收缩、宫颈扩张以及宫颈变薄，即宫颈消失。

But if it does happen, the resulting uterine contractions and increased lubrication can help draw up and hold sperm in the uterus.

但如果真的发了，由此产的子宫收缩和润滑增加有助于在子宫中吸收和保持精子。

Irregular, painless uterine contractions that may occur in the third trimester.

在妊娠晚期可能出现的无规律、无痛性的子宫收缩。

Some people are experiencing pain before the uterine contraction starts.

有些人甚至在子宫收缩开始之前就感到疼痛。

The first works hormonally, by blocking progesterone receptors, and the second mimics a molecule which induces labor, stimulating uterine contractions and causing the cervix to soften and dilate.

第一种药物通过阻断孕酮受体发挥作用，而第二种则模拟一种引发的子，刺激子宫收缩， 使宫颈软化并扩张。