How mammals give birth?

Birth:

This process is different in different mammals,in human beings it is as follows

1-The Labor begins:

As labor begins, rhythmic uterine contractions begin weakly and grow progressively stronger. Each contraction shortens the muscle fibers in the uterus, pulling the cervix (uterine opening) wider. In this early stage of labor the cervix dilates (opens) to about 4 cm (1.5 in).

2-Cervical Dialation:

As labor begins, rhythmic uterine contractions begin weakly and grow progressively stronger. Each contraction shortens the muscle fibers in the uterus, pulling the cervix (uterine opening) wider. In this early stage of labor the cervix dilates (opens) to about 4 cm (1.5 in).

3-Descent:

As labor begins, rhythmic uterine contractions begin weakly and grow progressively stronger. Each contraction shortens the muscle fibers in the uterus, pulling the cervix (uterine opening) wider. In this early stage of labor the cervix dilates (opens) to about 4 cm (1.5 in).

4-Crowning:

If a baby's position is head first during delivery, the mother's vagina fits like a crown around the baby's head, making the head visible as it emerges from the birth canal.

5-Birth:

As the head emerges, the neck flexes and the baby rotates to the side. This enables the shoulders to maneuver around the pubic bone. One shoulder emerges, quickly followed by the other shoulder and the rest of the body.

6-Delivery of Placenta:

In the final stage of labor, the uterus continues to contract and the placenta detaches from the uterus and is expelled.

There is a tiny set of mammals that are egg-laying - the duck-billed platypus and one or two others - but viviparous, or placental, reproduction ending in birth at least partly along the lines of the above (according to genus & species) is the system in all other mammals.