Cervical dilation is the opening of the cervix, the lower part of the uterus. This gradual widening allows the baby to pass from the uterus into the birth canal. It indicates labor progression, measured in centimeters from 0 to 10. The cervix also thins out, a process known as effacement, to prepare for delivery.
Recognizing Early Physical Signs
As the body prepares for labor, several physical changes may become noticeable. One common sign is the loss of the mucus plug, often called “bloody show.” This plug, which protects the uterus from bacteria during pregnancy, can be clear, pink, brownish, or tinged with blood as the cervix softens and dilates. It may come out as a single glob or in smaller pieces.
Increased vaginal discharge is another indicator that labor is approaching. This discharge may become more watery, sticky, or thicker, and can sometimes have a pink hue. While these signs suggest cervical changes are occurring, they do not always mean labor is immediate. They can manifest hours, days, or even weeks before active labor begins.
Understanding Contractions
Contractions drive cervical dilation, but not all contractions signal labor. Braxton Hicks contractions, often called “practice contractions,” are irregular and less intense. These contractions feel like a tightening in the front of the abdomen and may be relieved by changing positions, resting, or hydrating. They do not follow a consistent pattern and do not increase in strength or frequency.
True labor contractions, by contrast, exhibit a pattern of progression. They become increasingly regular, longer, and stronger in intensity. These contractions start in the lower back and wrap around to the lower abdomen, sometimes radiating to the pelvis or inner thighs. A true contraction lasts between 30 and 70 seconds and will not subside with changes in activity or rest. To time contractions, note their duration (start to end) and frequency (start of one to start of the next).
When to Contact Your Healthcare Provider
Knowing when to contact a healthcare provider ensures safety and timely care. For first-time parents, a common guideline is the “5-1-1 rule”: contractions every 5 minutes, lasting 1 minute, and continuing for at least 1 hour. For those who have given birth before, contractions might progress more quickly, so contacting a provider when contractions are 5 minutes apart for about an hour is often recommended.
Another event is the breaking of the amniotic sac, commonly known as “water breaking.” This can be a sudden gush or a slow trickle of fluid. If this occurs, contact a healthcare provider immediately, noting the time, amount, color, and odor of the fluid, especially if it is green or brown. Other reasons to seek medical attention include heavy vaginal bleeding (more than a bloody show), a decrease in fetal movement, or any other concerning symptoms like a fever or severe, unremitting pain.
Medical Assessment of Dilation
Once a person arrives at a medical facility, healthcare providers assess cervical dilation to determine labor progress. This assessment is performed through a digital vaginal examination. During this procedure, a healthcare provider inserts one or two gloved fingers into the vagina to feel the cervix.
The provider estimates the width of the cervical opening in centimeters. This measurement, ranging from 0 centimeters (closed) to 10 centimeters (fully dilated), indicates how far the cervix has opened. This assessment helps medical professionals gauge labor progression and make decisions regarding care.