A: Cervical exams are best to be thought of as decision-influencers, and yet are routinely done without context. Will knowing your cervical dilation affect a choice you have to make or what's recommended? Let's explore.
Cervical checks at routine prenatal appointments
it's often suggested during the last few weeks of pregnancy at prenatal appointments.... one reason for this is to ensure that the head of the baby is down. That's a decision point: if breech, there's work to be done through optimal positioning or an external cephalic version. That said, the head can be determined to be vertex via manual palpation of your belly (Leopold's Maneuver by a skilled provider as shown in the video below from Global Health Media) or by ultrasound- negating the need for a vaginal check for the same information.
Cervical checks before induction
Cervical status may be checked if you're considering/being recommended for induction. In this one, knowing what the cervix is doing is helpful so you receive the right medication to help the hormonal process get underway. Ripening meds would efface (soften/thin) the cervix, and often precede augmentation meds (Pitocin, causes contractions) when necessary. Going with augmentation when there isn't sufficient ripening underway would be less effective, so a check just before your induction may make sense in this case.
Let's also keep in mind that a cervical check in this case can also tell us about the station, or descent into the pelvis, of your baby. This is useful information, as a baby who's not yet engaged in the pelvis at the start of an induced labor (and even outside of induction) has a much higher rate of being born by Cesarean.
Cervical checks in labor
Yet another place where cervical status may be checked is when you are in labor, at antenatal. Often, dilation under a certain amount in the absence of progressive and strong contractions may mean going back home until later in your labor. Dilation over a certain amount can mean being admitted BUT isn't super necessary in the presence of progressive and strong contractions and other signs of cervical change (discharge, mucus plug, bloody show, water rupture [not a sign of cervical change but admissible nonetheless]) provided that the baby's head can be ascertained to be vertex. They usually rely on a cervical check to feel the head (at the same time as they feel for how open the cervix is), but this can be done with the ultrasound machine they have in antenatal. Short answer here: you can avoid this exam with the ultrasound and strong contractions. In labor, you may be asked multiple times for cervical checks. Usually, this is presented as "let's see where we're at" and can be declined any time. If there is a decision to be made, again, this can be good information: are you deep in a really hard labor and would decide to have an epidural if you hear that you're 5cm and not almost fully dilated? Then a check can be helpful. Are you involuntarily bearing down and sounding ready to push? A check will ensure that you're fully dilated and can do so safely.
If you do opt for a cervical check during labor, be sure to ask the provider to check for the station of the baby. Knowing the station may help you to employ Spinning Babies techniques for the appropriate level of the pelvis, and encourage your baby to descend using those strong labor contractions.
Reasons you think you want to have a check, but...
I know, I know. You want to check because you're curious... when will I go into labor?? Trust me, as a doula who lives life on-call, I wish a cervical check could actually be reliably predictive. Yet, there's just no way to tell when a softening cervix may begin to dilate, and no way to know if a closed cervix will be the star of a swift labor that starts that very evening.
What does the evidence say?
The evidence around the use of routine cervical checks at prenatal appointments is mixed, says Rebecca Dekker of Evidence Based Birth:
There have been two randomized trials on cervical exams towards the end of pregnancy:
One of the trials found that regular cervical exams (starting at 37 weeks) had no benefits
The other trial found that women who had weekly cervical exams (starting at 37 weeks) had a 3 times higher risk of water breaking before labor starts (also known as premature rupture of membranes, or PROM)
There have been zero trials testing the effects of cervical exams versus no cervical exams in labor.
Rarely are cervical exams an emergency. An update on cervical dilation, if not changing a possible management plan (further cervical ripening, concern for malposition, etc.) is not a necessary activity regularly throughout labor. Only discuss the possible need to assess cervical dilation if it is necessary, as we should only ever enter people's bodies when necessary.
1 in 5 women have been sexually assaulted. Likely higher due to underreporting. The rates are even higher in the queer and trans community. Best practice in my opinion is to assume everyone needs to have power over that exam for a variety of reasons, but possible history of sexual assault, whether they report to you or not, is a reasonable place to start.