Why 10cm?

[Tizzy]

This has been bugging me for awhile now: Why is 10 the magic number for dilation? Wouldn't it make more sense that some can dilate bigger and some dilate smaller?

[channelofpeace]

From my understanding, it isn't necessarily 10 cm. So 3 cm would be an opening of actually 3 cm, but after a certain point (6?) it is actually measured by how much cervix is left. So all but a cm is left, so the woman is 9 cm.

But maybe someone else could weigh in

[BirthIsAwesome]

some women DO dilate larger or smaller, but the doctors have to have everything clinical and measured---so they invented the magic 10 cm. Just like they invented the magic 40 weeks, even though the majority of women go into labor before or after 40 weeks.

[Comtessa]

Yes. 10 cm is an average. When they say "10" it really means "I can't feel your cervix anymore."

[Burnindinner]

Interesting question. I never would have thought to ask.

[secondimpression]

There is a very wonderful article about pushing before 10cm. I'm one of those women who bull-headedly ignored my body's urge to push at 9cm and wound up with a swollen cervix and intervention-filled birth as a result. Read the article a few weeks after giving birth and mentally crucified myself for not listening to my body and instead trusting the medical world. I'm guessing most women do dilate to a full 10cm...but some of us don't need to and I was one of them. Hindsight...

Anywho, I personally like to think of dilation more like percentages than centimeters if that makes any sense. Like 9cm is really 90% dilated, KWIM?

[nikirj]

Yeah, there's kind of a magic no-(wo)mans-zone at around 6cm where it goes from how open your cervix is to how much cervix is left. So you can actually dilate more (or less) than a cm at around that point and only get credit for 1 cm, depending on how open your cervix eventually needs to get. Different practitioners make that shift at slightly different places, so you'll often get disagreement between two exams at around that point, too. That's why I think that unless something is wonky all the VEs should be done by the same person if at all possible.

[*MamaJen*]

There's another similar thread going on right now: http://www.mothering.com/discussions....php?t=1219541

[treespeak]

Thanks for posting this question Tizzy. I've been wondering the same thing this week. It's counter-intuitive for me to think that with the great variation in sizes/shapes of women's bodies (as well as the babes they're birthing) that 10cm would be some magic number all women have to reach.

[kitkatkaddoodle]

As someone who checks for this sort of thing (L&D nurse), it's really NOT 10 cms so much as "no more cervix" once you get past 8cms or so. If you've only got a little, flexible ring of cervix, pushing past it can work, but you risk tearing, swelling, and other issues.

[beckyand3littlemonsters]

I always woundered this especially when i was pregnant with my dd chloe, i remember going to antenatal classes and the mw mentioning checking how many cm's dialated you were and it confused me some what because i woundered how they measured, i thought they used some type of special cervix ruler lol