There are three stages of labor starting from the time of the beginning of contractions and cervical dilatation up to the delivery of the placenta:
The first stage of labor begins with regular contractions and is defined by cervical dilation up to the time the cervix is fully dilated, 10 cm dilated.
The first stage of labor is further divided into three phases:
- Latent Phase
- Active Phase
- Deceleration or Transition Phase
Latent phase of the first stage of labor: The latent phase begins when there are cervical dilation and contractions, and it ends when the active phase begins.
Active phase of the first stage of labor: The active phase begins when the cervix starts to dilate quicker, usually after 3-4 cm dilatation.
Transition or deceleration phase of the first stage of labor: The transition phase of labor usually begins at a cervical dilation of about 8 cm, and it ends at cervical dilatation of 10 cm when the cervix is fully dilated.
The second stage of labor begins when the cervix is 10 cm dilated or fully dilated, and it ends when the baby is born. It is during this stage that the mother is pushing and the baby descends through the birth canal. Crowning happens at the end of the second stage as the baby's head descends to the opening of the vagina and does not recede with contractions. The second stage of labor can normally last up to 3-4 hours.
The third stage of labor starts at the delivery of the baby and ends when the placenta is expelled. This stage normally lasts from several minutes up to 30-60 minutes.