The first stage of labor is the onset of labor to full cervical dilation. This is divided into 2 phases:
Latent phase – effacement and early dilation of the cervix 0-1 cm dilation: averages 6.4 hours first time mothers, average 4.8 hours in mothers had a previous vaginal birth.
Active phase – 3-10 cm dilation, average 4.6 hours in first time moms, average 2.4 hours in mothers with a previous vaginal birth.
Maximum rate of dilation 3 cm/hour in first time moms 5.7 cm/hour in moms with previous vaginal birth.
Second sate of labor is from the time you have complete dilation (10 cm) until the time you delivery your baby. On average it will take 1.1 hours in first time mothers, and the average is 0.39 hours in mothers with previous vaginal birth
The third stage of labor is the time from after the baby was born through the delivery of placenta. The average time for all women should be less than 30 minutes.
to learn more watch the March of Dimes video on the stages of labor: