I've heard it a thousand times. "I'm 3cm dilated!", "I'm NOT even dilated yet, and I'm 40 weeks.", "I've been having lots of contractions, but when I was checked, I'm just 1cm".
Why on earth are we so caught up with how open our cervix is?! When I hear these things from clients I ask them 4 things. These are the 4 things that you should ask before and after a pelvic exam.
1- Station. The station is the place in the pelvis that the baby it sitting. A baby can be "floating", which means they are not engaged in the pelvis, therefor the station is -4 or higher. If a baby is "engaged" they are at a 0 station, which is at the ischial spines- the midpoint of the pelvis. When a baby is +3,+4, they are very low and mom usually has the urge to push. When a pelvic exam is performed in labor, it's good to know what station he/she is at. For example: Susy gets to the hospital and is 5cm dilated and is a 0 station. Several hours pass and Susy decides to have another pelvic exam, she is still 5cm, but wait! Baby has moved lower to a +1 station. Progress has been made. What if she was told, "you're still at 5cm"? Susy may feel discouraged, like her body hasn't progressed, when in fact she has! Her baby has lowered AND some other things happened...
2- Effacement. This is measuring the consistency of the cervix. As the body prepares for labor, the thick and firm cervix will start to thin out and soften. Think about a very ripe peach vs. an unripe peach. You could easily stick your finger into the soft juicy peach to tell that it's done. An unripe peach is hard, not juicy, and difficult to open. Effacement is measured in percentage. An uneffaced cervix is hard, not usually open, and about 1cm long. 50% effaced means the cervix is soft and short. 100% effaced means the cervix is completely thinned out, some say paper thin. it's very common for a women to not be completely effaced until active labor has been well established.
3- Position of the cervix. This one is easy. The cervix is either posterior or anterior. A posterior cervix is still facing near the anus and is hard to feel for. The anterior cervix is easy to access and is completely pointing toward the vagina/birth canal.
4- Dilation. We all know what this is, as it's been engraved on our minds through media, care providers assessments, pregnancy books, and birth stories. 10cm means that the cervix is completely opened around the baby's head. This number is an ESTIMATION! Not every cervix will need to open to 10cm for a baby to pass through, it will simply need to be fully opened. Once a woman passes 6cm, the dilation is no longer measuring the open space, it's measuring the ring of cervix still around the babies head. So, if the cervix still has about 1cm of tissue still around the baby's head, the cervix is 9cm dilated. This isn't really something a mother needs to know during labor, but it's nice to know before labor begins and can help visualize what needs to happen to the cervix to be considered 10cm or "complete". I tell my clients a few things about dilation. It's an estimate! One nurse might say you're 4cm, while the next says you're 3cm. What dilation tells us is what your cervix is at THAT EXACT MOMENT. It doesn't tell us what you were the second before, or the second after. It can also hinder a woman who's been laboring for several hours to find out that her cervix hasn't dilated more. It can take 12 hours for the cervix to dilate to 4cm, but then it can take 30 minutes for it to dilate completely.
This last one is totally optional, and not all nurses or care providers will be able to tell you this as many factors come into play (cervix needs to be open to 6cm, no bag of waters bulging and no significant head molding) . If you're in labor and it's been very long, with sporadic contractions, maybe some back labor. Ask during your next vaginal exam if the care provider can tell you what position your baby is in. Sometimes a posterior baby (aka sunny side up) will result in a longer labor with more back pain than a baby who is anterior. There are numerous things to do when you're in labor and suspect baby is malpositioned. Check out Spinning Babies for more details.
There you go! 4 things to ask about during a pelvic exam. See, it's not all about dilation. There is much more going on than a cervix opening. Always ask questions. Assess your well being before anything.
pelvic exam geek, Birth Doula, and Placenta Specialist