Six labor stations selected to represent conditions of the cervix and vagina prior to labor, during labor, and at birth. Stations illustrated are:

• STA -5 prior to onset of labor
• STA -4 cervix partially effaced
• STA -3 cervix fully effaced
• STA 0 fetal head at plane of ischial spine
• STA +2 cervix nearing full dilation
• STA +5 crowning of fetal head