| Labor has three stages.
The first stage begins when the cervix begins to dilate and becomes effaced, thinning out. The first part of the first stage is called the latent phase, and may begin late in pregnancy. It has no specific time limit.
The second phase is called the active phase of the first stage, and it begins when the cervix is dilated to 4 centimeters, or is 80% effaced.
|