Cervical Check in Labor
What are they?
Cervical checks are one way midwives ensure the mother is experiencing a normal labor. While not all midwives agree on their value most women will experience at least one.
The midwives who find them helpful explain it is possible for women to have contractions without being in active labor. They feel a cervical check can be used to help ensure a woman is in active labor before she is admitted to a hospital or birth center, potentially preventing an unneeded augmentation of labor. Cervical checks can allow the midwife to identify a woman who may need additional assistance, such as a woman with pre-labor contractions that are exhausting the mother. Sometimes women are reassured by hearing the changes their contractions have made.
Midwives who find cervical checks unhelpful explain they can be uncomfortable and distressing to mothers. Some midwives feel they are unnecessary to determine the labor progress of the woman. Sometimes, women are frustrated by hearing their contractions are not causing changes.
During labor, the attendant (a doctor, midwife or nurse) will insert their gloved fingers into the vagina to feel for changes in the cervix. This is most commonly done while the woman is lying on her back with knees bent, although some attendants are comfortable checking in other positions.
Your midwife, doctor or nurse will be looking for signs the contractions have caused changes in the cervix, which would indicate labor is progressing. These signs include cervical position, dilation, effacement, station of the baby and sometimes the position of the baby. Understanding what each of these changes means can help you understand your labor progress.
Before labor begins, the cervix drops into the vaginal canal at an angle that makes it point toward the back (posterior). One sign of progress is that it moves anterior, meaning it has realigned to allow the baby to drop into the vagina (birth canal). This is generally a change that happens early in labor.
Dilation and Effacement
Dilation and effacement work together to open the cervix to allow the baby to drop into the vagina. During pregnancy the cervix lengthens and thickens to protect the baby. During labor, it softens and shortens to allow the baby to pass through. Effacement refers to cervical thickness or thinness. Effacement is measured by percentage, with 0% being thick and 100% being very soft and thin or "gone."
During labor, the cervix opens wider to allow the baby to pass through. Dilation refers to how big the opening is. Dilation is measured from 0 (closed cervix) to 10 (fully opened cervix). Generally, effacement will happen before any great progress in dilating.
0-4 cm: Early Labor
4-8 cm: Active Labor
8-10 cm: Transition
10 cm: Fully Dilated
The station of the baby refers to the progress of the head through the pelvis. The attendant will try to estimate where the baby's head is in relation to the ischial spines of the pelvis (the narrowest part). Before the baby's head reaches the ischial spines, the station is given in negative numbers. At the ischial spines the station is measured as 0. After the top of the head has passed through the area of the spines, station is given in positive numbers.
Position of Baby
Some attendants will also use a cervical exam to confirm the position of the baby in the pelvis. By feeling the position of the bones on the top of baby's head, the attendant can determine which direction the baby is facing (to the front, back or leaning to a side).
The currently accepted way of measuring progress in labor is based on the information learned during a cervical exam. The information gained from an exam is compared to the generally accepted standards to ensure the woman is experiencing a normal labor. When dilation falls "off the curve" or passes the "action line" in a partogram (graphical representation of dilation over time), the health care provider is expected to respond accordingly. For this reason, some attendants will do many exams, or "checks" during a labor. The World Health Organization standard for normal labor lists vaginal exams as an essential tool to ensure normal progress, and recommends assessment be done every four hours during active labor.
It is important to remember that when exams are performed more frequently, the information gained during a cervical check does not always line up with true labor progress. For example, in some areas progress is for cervical dilation of one centimeter per hour during active labor. Yet, many women will have a few hours without a change in dilation, and then two or three strong contractions that open the cervix fully. If cervical exams show no progress (no dilation) for one or two hours, some mothers become frustrated and concerned for no reason. Some attendants also become frustrated and concerned since they have been taught that a normal labor will produce dilation along a regularly spaced interval, and may encourage the use of medications to speed labor, so that labor can progress "normally."
In the case of a medical induction of labor, cervical exams will often be performed more frequently than every four hours once a woman is experiencing regular, strong contractions. Ensuring the artificially stimulated contractions are causing cervical change helps the midwife make timely decisions about changing induction strategies, and can help prevent a woman from having four hours of artificially produced, unproductive contractions.
Cervical exams increase the risk of infection in the mother. Having the hands washed and gloved makes little difference, since the fingers must pass through the opening of the vagina. The cervical mucus washes all bacteria down and out of the vaginal canal to rest at the opening of the vagina. A cervical exam pushes that bacteria right back up to the cervix. Because of this, most attendants will not do vaginal exams more than once or twice if your bag of waters has broken (another risk factor for infection).
Cervical exams can uncomfortable, especially during contractions when the most information can be gained. Some attendants feel justified in asking laboring women to change position so they can perform a "necessary" cervical check. Other attendants are skilled at checking a cervix in many positions.
Questions to Ask your Midwife
- How often do you normally perform vaginal exams?
- When would you suggest cervical checks outside your normal schedule?
- Can you assess my cervical change while I am in hands and knees position? In the tub? In the shower?
- Who performs the exams? You? A nurse? Students? Your back-up physician?
- If using cervical checks to monitor labor, at what point will you recommend augmentation of labor?
- If using cervical checks to verify labor, what happens if I come to the birth place and am not yet dilated enough to call it active labor?
- What is your protocol if I refuse vaginal exams? How will you assess labor progress?