Information on a pregnancy dilation chart typically includes the different dilation sizes of the cervix in centimeters and may also include a diagram of the baby moving in the birth canal. There are three main stages of labor, with the first stage divided into sub stages based on dilation size, notes the AmericanPregnancy.org.
The first stage of labor in pregnancy is divided into three stages: the beginning of labor until the cervix is dilated to 10 cm, the time when the cervix is dilated 10 centimeters until the baby is born and the delivery of the placenta. The first stage is the longest period of labor and is further divided into stages. The early labor phase lasts until the cervix has dilated to three centimeters. The active labor phase lasts from when the cervix is dilated three centimeters until it is dilated seven centimeters. The transitions phase begins when the cervix is dilated seven centimeters until it is dilated 10 centimeters.
A pregnancy dilation chart can help expectant parents understand what the different dilation sizes look like and what to expect during labor and delivery. The cervix must be dilated to 10 centimeters before delivery of the baby can begin, notes MayoClinic.org.