A cervical check is a manual physical examination typically performed during late pregnancy and active labor. Its primary purpose is to evaluate the readiness and progression of the cervix for childbirth. A healthcare provider uses their fingers to determine the physical status of the cervix, which informs decisions about labor management. While the check offers valuable real-time data, it is only a snapshot of the current state and does not accurately predict the exact timing of labor.
Necessary Context and Safety Precautions
A cervical check must be performed only by a trained healthcare professional, such as a doctor, midwife, or nurse. The provider must use sterile gloves and maintain a sterile technique to minimize the risk of introducing bacteria into the reproductive tract. Excessive vaginal examinations during labor may increase the chance of infection, especially after the membranes have ruptured.
The procedure is contraindicated when the risk outweighs the benefit. A check should not be performed if there is unexplained antepartum hemorrhage (vaginal bleeding after 20 weeks of gestation) or known or suspected placenta previa, where the placenta covers the cervical opening. If the membranes have ruptured and the baby’s head is not properly engaged, a check could increase the risk of a cord prolapse.
The check is generally reserved for times when the information will directly influence patient care. This includes when a patient is admitted to a hospital with signs of labor or reports strong, regular contractions. The assessment is also used periodically during active labor to monitor the speed of cervical change and the baby’s descent.
Step-by-Step Guide to the Procedure
The process begins with the patient lying on an examination table, typically in the dorsal lithotomy position with feet supported in stirrups. After thorough handwashing, the provider dons sterile gloves, often applying lubricating gel, and obtains explicit consent before starting the examination.
The examiner gently inserts the index and middle fingers into the vaginal canal, aiming toward the cervix. The cervix may be positioned high or tilted backward, requiring the examiner to reach further to locate the opening (os). If the patient is not in active labor, the cervix is usually closed, firm, and thick, feeling similar to the tip of a nose.
Once located, the examiner assesses three distinct measurements simultaneously. Dilation is measured by sweeping the fingertips from one edge of the cervical opening to the other. The distance between the fingertips is estimated in centimeters, indicating the width of the opening. Effacement is assessed by determining the thickness of the cervical walls, feeling how much the cervix has thinned out.
The examiner assesses the fetal station by determining the position of the baby’s presenting part, usually the head, relative to the mother’s ischial spines. These are fixed bony prominences inside the pelvis. The provider determines if the head is above, at the same level as, or below these spines.
Understanding Dilation, Effacement, and Station
The three measurements obtained during a check provide a comprehensive picture of labor progression.
Dilation
Dilation refers to the widening of the cervical opening, measured in centimeters. The scale ranges from zero centimeters (closed cervix) up to 10 centimeters, which is considered “complete.” Ten centimeters indicates the cervix is fully open for birth and is no longer palpable around the baby’s head.
Effacement
Effacement describes the thinning and shortening of the cervix, typically measured in percentages. Before labor, the cervix is long (often 3 to 5 cm thick) and considered 0% effaced. As labor progresses, the muscle fibers shorten, resulting in 100% effacement, meaning the cervix is paper-thin and incorporated into the lower uterine segment. First-time mothers often achieve effacement before significant dilation, while those who have given birth previously may dilate sooner.
Station
Station indicates how far the baby’s head has descended into the pelvis, using the ischial spines as the fixed zero point. Measurements range from -5 to +5. A negative number, such as -3, signifies the head is high up, three centimeters above the zero station. Zero station means the baby’s head is aligned with the ischial spines and is considered “engaged.” Positive numbers, such as +3, indicate the baby has moved past the spines and is low in the birth canal, nearing delivery.