A cervical check, also known as a digital vaginal examination, is a procedure performed by a healthcare provider to manually assess the condition of the cervix. This examination involves inserting two gloved fingers into the vagina to physically feel the cervix, the lower part of the uterus. The primary goal is to determine the state of cervical changes, offering a snapshot of the body’s preparation for labor and delivery. This assessment becomes a more frequent topic during the third trimester as the due date approaches.
Routine Cervical Checks in Late Pregnancy
For a low-risk, uncomplicated pregnancy, routine cervical checks typically begin between the 36th and 37th week of gestation. Some providers offer a check at each weekly prenatal appointment until delivery to establish a baseline measurement of the cervix’s status.
These checks are not universally performed or medically mandated in the absence of specific concerns. The information gathered is generally not a reliable predictor of when labor will begin. A patient could be several centimeters dilated for weeks, or be completely closed and go into labor the next day.
Checks may be initiated earlier than 36 weeks if there are specific medical indications, such as symptoms suggesting preterm labor. If a patient is considering a medical induction, a check assesses the cervix’s readiness to determine the most appropriate method. Otherwise, the routine weekly exam remains optional.
What the OB is Assessing
During a digital examination, the provider observes three distinct measurements that collectively describe the progression toward birth: dilation, effacement, and fetal station. These metrics provide a comprehensive view of the cervix and the baby’s position in the pelvis. The combination of these factors is sometimes used to calculate a Bishop Score, which helps predict the likelihood of a successful labor induction.
Dilation
Dilation refers to the opening of the cervix, measured in centimeters (cm). A completely closed cervix is 0 cm dilated, and full dilation, which signals the beginning of the pushing stage of labor, is 10 cm. This measurement is subjective, estimated by the provider’s fingers, but it is the most commonly discussed metric of labor progress.
Effacement
Effacement describes the thinning and softening of the cervix, measured as a percentage. Throughout pregnancy, the cervix is relatively long and thick, considered 0% effaced (often measuring 3 to 5 centimeters in length). When the cervix is completely thinned out, becoming paper-thin, it is considered 100% effaced, making way for the baby’s descent.
Fetal Station
Fetal Station indicates the baby’s position relative to the mother’s pelvis, specifically to the ischial spines. This measurement uses a numerical scale. Zero station means the lowest part of the baby’s head is level with these spines, indicating the head is engaged. Negative numbers (e.g., -3) mean the head is higher in the pelvis, while positive numbers (e.g., +1) mean the baby is descending lower into the birth canal.
Cervical Examinations During Labor
Once a patient is admitted for active labor, the purpose of cervical checks shifts to monitoring progression and informing care decisions. Checks are typically performed upon admission to confirm active labor and establish a baseline measurement for dilation, effacement, and station.
During the first stage of labor, checks are often offered every two to four hours, or when a change in the patient’s condition suggests progression. Specific events also prompt an examination, such as requesting pain medication, membrane rupture, or when the patient feels an involuntary urge to push, ensuring full 10 cm dilation has been reached.
Providers must balance the need for progress data with the risks of repeated internal procedures. Each check introduces a cumulative risk of introducing bacteria, increasing the chance of infection, particularly after the amniotic sac has ruptured. Frequency is a careful clinical decision, minimized to when the information directly influences the immediate plan of care.
Patient Autonomy and Refusing Exams
Routine cervical checks, both prenatal and during labor, are an optional procedure that requires informed consent. A patient has the right to decline any medical procedure at any point in their care. The healthcare team should fully explain the benefits and risks of the procedure beforehand.
For those who wish to limit internal checks, alternative ways exist to monitor labor progress. Observing external signs, such as the frequency and intensity of contractions, changes in vocalization, or the “purple line” on the lower back, can offer clues about progression. Patients can ask providers how the results of a check will change the current care plan to decide if the information is necessary.
If a complication arises, such as unexpected bleeding or concerning changes in fetal monitoring, a cervical check may be strongly recommended for diagnostic information. Even in these cases, the patient retains the right to refuse, but the provider must clearly communicate the potential consequences of declining the recommended examination.