Cervical dilation is the opening of the cervix, the lower part of the uterus, during childbirth. As labor progresses, the cervix gradually widens to allow the baby to pass into the birth canal. Many wonder if they can feel this change, so understanding the sensations and how medical professionals assess progression is key.
The Sensation of Dilation
While uterine contractions are distinctly felt, directly sensing the cervix opening is generally not possible. The uterus has a rich nerve supply, transmitting contraction feelings. However, the cervix has a more limited nerve supply, meaning the stretching and widening of cervical tissue are often not perceived.
Instead, individuals typically experience sensations associated with the overall labor process, indirectly indicating cervical changes. These include cramping similar to menstrual discomfort, pelvic pressure, or a generalized lower back ache. Stronger, more frequent contractions exert pressure on the cervix, encouraging it to open and thin. This pressure, along with the baby’s descent, contributes to felt sensations. Some may also describe sharp, shooting pains in the vaginal area, sometimes called “lightning crotch,” as the baby moves lower and puts pressure on pelvic nerves.
How Dilation is Measured
Since direct sensation of cervical dilation is not reliable, healthcare providers assess labor progression through internal examinations. A gloved hand is used to manually feel the cervix and determine its state. Dilation is expressed in centimeters, ranging from 0 cm (closed) to 10 cm (fully dilated), which is wide enough for the baby’s head to pass through.
Beyond dilation, providers also assess effacement and fetal station. Effacement refers to the thinning and shortening of the cervix, measured in percentages from 0% (thick) to 100% (paper-thin). Fetal station indicates how far the baby’s head has descended into the pelvis, measured relative to the ischial spines. A 0 station means the baby’s head is aligned with these spines, with negative numbers indicating higher positions and positive numbers indicating lower positions.
Other Indicators of Labor Progression
Since cervical dilation itself cannot be felt, other observable signs and symptoms indicate labor progression. Contractions are a primary sign, with their frequency, intensity, and duration offering clues about labor’s advancement. True labor contractions typically become progressively stronger, longer, and closer together, unlike irregular Braxton Hicks contractions. They may feel like strong menstrual cramps or a tightening that begins in the back and moves to the front.
Another sign is the “bloody show,” a discharge of mucus mixed with a small amount of blood. This occurs as the cervix softens, thins, and begins to open, causing tiny blood vessels to rupture. While it indicates cervical changes, it does not necessarily mean labor is immediate.
The “water breaking,” or rupture of the amniotic sac, is another clear sign, though it often happens during labor rather than before contractions. The fluid may be a sudden gush or a slow trickle.
When to Seek Medical Advice
It is generally advised to contact a healthcare provider or go to the hospital when contractions become regular, strong, and consistently closer together. For first-time parents, a common guideline is the “5-1-1 rule”: contractions every 5 minutes, lasting 1 minute each, for at least 1 hour. For those who have given birth before, active labor might be indicated sooner, such as every 5 to 7 minutes.
Immediate medical attention is necessary if the water breaks, especially if the fluid is discolored (green or brown) or has a strong odor, indicating a potential issue. Significant vaginal bleeding, similar to a heavy menstrual period, also warrants immediate contact. Any concerns about reduced fetal movement or other unusual symptoms should also prompt a call.