A cervical check is a routine procedure in late pregnancy and labor that allows medical providers to monitor how the body is preparing for childbirth. This manual examination is the primary method doctors and nurses use to gather data on the progress of labor or pre-labor changes. The information obtained helps the care team make decisions about managing labor, such as when to admit a patient to the hospital or when to begin pushing.
Understanding Cervical Readiness
The manual examination focuses on assessing three specific factors that indicate the cervix’s readiness for birth.
Dilation
The first factor is dilation, which refers to the opening of the cervix, the muscular ring that connects the uterus to the vagina. Before labor, the cervix is closed, but it must open significantly to allow the baby to pass through.
Effacement
Effacement describes the thinning and shortening of the cervix. A cervix that is not yet ready for labor is long and thick. As the body prepares for birth, the cervix softens and thins out.
Station
Station tracks the baby’s position relative to the mother’s pelvis. It measures how high or low the baby’s head is in relation to the ischial spines, which are bony points inside the pelvic structure.
The Manual Examination Procedure
The assessment of cervical readiness is performed through a manual, or digital, examination. The patient is typically positioned on their back with their feet in stirrups during a prenatal visit, or with their knees bent and legs apart while in a hospital bed during labor. This positioning allows the medical provider clear access to the vaginal canal and cervix.
The provider puts on sterile gloves and applies lubricant to minimize discomfort during the procedure. They then gently insert one or two fingers into the vagina, guiding them until they reach the cervix. The examination is brief, usually lasting only a minute or two, but it is common to feel a sensation of pressure or mild discomfort.
Using their fingers, the provider assesses the cervix to estimate the three measurements. Dilation is measured by estimating the width of the cervical opening. Effacement is determined by feeling the thickness of the cervical walls.
The provider feels for the baby’s presenting part, usually the head, to determine its station within the pelvis. These checks are performed near the end of pregnancy and are repeated periodically during active labor to monitor progression. The timing of the check is a clinical decision, as examinations carry a small risk of infection once the membranes have ruptured.
Interpreting the Three Measurements
The results of the manual examination are often communicated to the patient as a set of three numbers, representing dilation, effacement, and station, respectively.
Dilation
Dilation is the most commonly discussed number and is measured in centimeters, ranging from 0 to 10. A cervix that is fully closed is 0 cm dilated, while 10 cm dilation signifies that the cervix is completely open and ready for the pushing stage of labor.
Effacement
Effacement is expressed as a percentage, indicating how much the cervix has thinned out from its original state. A cervix that is still long and thick is considered 0% effaced, and a cervix that is paper-thin is 100% effaced. The cervix must be significantly effaced before it can begin to dilate fully.
Station
Station is measured using a scale that runs from -5 to +5, with the ischial spines serving as the zero reference point. Negative numbers (e.g., -3 or -2) mean the baby’s head is still high up in the pelvis, above the spines. Zero station means the baby’s head is “engaged,” or level with the spines. Positive numbers (e.g., +1 or +2) mean the baby has descended past the reference point and is lower in the birth canal, indicating that delivery is closer.