A cervical lip is a specific anatomical finding that can occur during labor, referring to a portion of the cervix that has not yet fully thinned and dilated. This term describes a stage in childbirth where a small rim of cervical tissue remains present, often on one side of the baby’s presenting part. While it is a common occurrence, its presence can sometimes influence the progression of labor.
Understanding the Cervix and a Cervical Lip
The cervix, often called the “neck” of the uterus, is a muscular structure connecting it to the vagina. During pregnancy, the cervix remains firm and closed, helping to keep the developing baby securely inside the womb.
As labor begins, the cervix undergoes significant changes, including effacement (thinning and shortening) and dilation (opening). Full effacement and dilation mean the cervix is completely open, providing ample space for the baby to pass through. A cervical lip occurs when a segment of the cervix, typically the anterior portion, does not fully efface or dilate, remaining as a thickened edge even when the rest of the cervix has opened considerably. This undilated rim can be felt during a vaginal examination.
Why a Cervical Lip Forms
The formation of a cervical lip is often linked to uneven cervical effacement and dilation. While the cervix is commonly thought to dilate circularly, it often opens in an elliptical or oval shape, typically from back to front. This uneven opening can result in the anterior (front) part of the cervix being the last to retract fully.
A baby’s position can also influence how the cervix dilates and whether a lip forms. If the baby’s head is not applying even pressure to the cervix, such as in an occiput posterior position where the baby faces the mother’s front, it can lead to an uneven opening. This uneven pressure can cause a portion of the cervix to become trapped between the baby’s head and the maternal pelvis. Additionally, the timing of pushing efforts can contribute to a cervical lip; if a person pushes before the cervix is fully dilated, it may cause the cervical tissue to swell or become caught.
Managing a Cervical Lip During Labor
When a cervical lip is identified during labor, healthcare providers typically assess the situation through a vaginal examination. The most common approach involves patience and allowing the natural progression of labor. The cervical lip often resolves on its own as contractions draw the remaining cervical tissue up and around the baby’s head.
Changing maternal positions can also be beneficial, as it may help the baby shift and apply more even pressure to the cervix, encouraging the lip to retract. Positions such as being on hands and knees, leaning forward, or side-lying can sometimes facilitate this process. In certain situations, a healthcare professional may attempt a gentle manual reduction of the cervical lip, carefully guiding the tissue over the baby’s head between contractions. This technique is performed by trained medical staff to assist labor progression, though it can be uncomfortable. The goal is to ensure the lip does not become swollen or impede the baby’s descent.
Cervical Lip Beyond Labor
While a cervical lip is primarily discussed in the context of labor and childbirth, instances of it being observed outside of active labor are rare. In these non-labor scenarios, it typically refers to an anatomical characteristic or a finding during routine gynecological examinations. Such findings are usually benign and do not indicate a problem.
For example, a healthcare provider might notice a specific contour of the cervix during a pelvic exam, which, while not a “lip” in the labor sense, could be described as an anatomical variation. These non-labor presentations generally do not cause symptoms or require any medical intervention. In very rare cases, extreme stretching of the cervix can occur during childbirth, leading to a prolapse, but this is distinct from the typical cervical lip observed during labor progression.