If you've seen movies that feature childbirth, you can probably recall when the actor playing the doctor says, "They're 10 centimeters"—they are talking about dilation of the cervix. The cervix ...

The Friedman curve, the gold standard for rates of cervical ... to 1996. Dilation in the active phase was much slower on the modern curve than on the Friedman curve (mean time from 4 cm to ...