First stage of labor is divided into latent, active and transition phase

This phase starts from onset of uterine contraction up to

4 cm dilatation of the cervix

This phase starts from 4 cm up to 10 cm dilatation of the cervix.

Latent phase for nullipara lasts for about 4-8 hours

Active phase for nullipara lasts for 1.2 cm per hour

Stage 2 is 10 cm dilatation of the cervix until delivery of the baby.

Stage 3 is the delivery of the baby until the delivery of the placenta that lasts for at least 2 hours for multipara.

It is known as the thinning of the cervix and is expressed in percent.

Uterine contractions are the basic force moving the fetus thru the birth canal.

Poor fetal position is one cause of dysfunctional labor

It is defined as labor completed in less than 3 hours

A contraction ring can interfere with fetal descent

It refers to assisting labor that has started spontaneously but is not effective.

A normal cord contains one vein and two arteries