Cervical exams check for fetal position, cervical dilatation, effacement, and station. Membrane stripping can also be done. There is usually a cervical exam at 36 weeks and again at the due date. If you are having contractions, the doctor may want to exam you to see if your cervix is opening.
The cervix is usually checked at 35-36 weeks along with the Group B Strep screen see Group B Strep video here. At this time, the doctor will be checking to see if the baby’s head is down see a discussion of fetal position here. The doctor will also see if your cervix is dilating or effacing see dilatation, effacement, station.
The cervical check is done with you laying down with your feet in the stirrups. The doctor will use two gloved fingers to enter your vagina and feel the cervix. This can be fairly uncomfortable near term. Each doctor has their own style of when to check the cervix. In my practice I check everyone a month before delivery and then at the due date if not delivered. Some doctors will check the cervix each week in the last month. The truth is the information obtained will not change the medical management. If the cervix is closed or 4 centimeters it won’t change what will be done. This is the reason I don’t check my patients every week. It is uncomfortable for the patient and does not supply information that will effect decision-making. Sometimes I have patients who want to be checked, and I am happy to oblige, after all, it doesn’t hurt my fingers. If you want to be checked, just let your doctor know.
At term, when your cervix is checked, something called “membrane stripping” or “sweeping” can be done. This often helps start the labor process, but it can be pretty painful. This involves the doctor putting one or two fingers through the cervix and separating the membranes from the upper cervix and lower uterus. This is thought to help release prostaglandins, the chemical that starts the labor process. It is common to have some spotting or mild bleeding (bloody show) after this procedure. This is done in the doctor’s office at your regular appointment.
Patients who are scheduled for c-section usually do not need a cervical exam unless there is worry that they are in labor. Patients with a placenta previa should not have a cervical exam. If you have a placenta previa, be sure you make this very clear to anyone who is considering doing a cervical exam on you. Cervical exams with placenta previa have the possibility of causing dangerous bleeding.