Can you have your pelvis opening measured?

[CathyandHeathcliff]

I’m just wondering if this is an option.
I’m currently trying to make a decision between vaginal birth or elective c section. I was wondering if they can measure your pelvis capacity before the birth to see if you can genuinely fit a baby through it? I know some women have such a narrow pelvis that it just can’t happen.

Your pelvis is made of separate sections which flex and expand during pregnancy (due to relaxin) Then it opens further as you go into labour, to allow baby through, so I don't think measuring is something that would give an accurate idea (or even be possible)

I'm sure more knowledgeable people will be able to come along and explain better, but I've read (and heard) many stories of women who are tiny (size 8 or smaller) delivering big babies without need of intervention.

How you give birth is completely your choice obviously OP but I'm not sure (apart from in extreme circumstances) that pelvis size is a consideration.

Apparently it's to do with the shape rather than size. It's rare to be too small to deliver a baby, though. Your body will normally grow the baby to the size you can manage.

This is where I heard about the shape:

Pelvis measuring is inaccurate and usually a baby will not grow too big to get through.

And I say that as someone with a pointy one (androgenous?), the narrowest of them all. I looked into the issue after DD, but it doesn't seem to matter much.

Your bones will literally move during the end of pregnancy/labor to accommodate the baby's exit. Even if you have narrow hips before pregnancy, they will shift to allow the baby through. That's part of all the aches and pains we experience.

I was an emergency csec when I arrived in 1981.
Afterwards, my mum was x-rayed holding yardsticks and was told that she could never have given birth naturally, even to a preterm baby.
I'm not sure if I have the same issue (DD emcs as well) but the size of our hips is apparently no indicator of this at all.

Mine is sub optimal as discovered in labour with dc1 which coupled with the fact that I grow babies with giant heads (>90th percentile even at 39 weeks) has resulted in 2 emergency sections. However I'm led to believe I'm fairly rare and unlucky.

Both my grandmothers are tiny and had giant babies albeit with average heads easily.

@SevenOf1981 that’s the kind of thing I’m talking about, I wonder if they’ll do that for me beforehand, although I know they most likely won’t.

Similar to Seven I was an EMCS in 1988 and my mum had an x-ray clenching a metre rule in her buttocks.... she was told she'd not deliver naturally but my brothers and I all had 90+ centile head and she has a tiny frame - 7.5 stone ish and 5'1". Not sure if there's something similar these days (assume not x-ray as they tend to avoid in pregnancy).

I am 5'2" and slim but a much bigger frame, I've delivered my 8, 8.5 and 8.13 babies without even a stitch. Think it's a mixture of factors.

My sister is 5ft tall and size 6-8 - she delivered a bouncing 9lb-er at home with no problems.

Isnt it related to your shoe size? I was always asked in early pregnancy for my shoe size. Size 6. I am 5ft 3in tall and weighed 8.5st when I got pregnant. I was young though. My babies weighed 8lb 10, 8lb 10 and 9lbs. Gave birth no trouble

No they won’t measure pelvis size. Whether you can give birth vaginally or not doesn’t just depend on you, it also depends on baby’s head size-during labour, baby’s head squashes a bit and your pelvis and ligaments will relax a bit, there’s no way they would know beforehand how much this would happen..

I was told all through pregnancy you can’t grow a baby too big to give birth to and I did! Had a good crack at labour (for a week)and one of the few things I remember from my emcs was that baby would never have come out naturally! Funnily enough my mother had exactly the same problem but her much smaller Mother didn’t.

All my life I've been told I had childbearing hips but my 7lb 4oz child got thoroughly stuck...so I wouldn't set too much store by measurements!

The size of a women's hips is unrelated to the shape of her pelvic outlet so the term child bearing hips is meaningless. There are 4 types pelvis outlet and the vast majority of women have a gynaecoid type - ideally suited for childbirth. If you had one of the others there might be an issue but there might not. The proof is really in the pudding. No idea why you think this might be an issue based on no evidence though! Sometimes the pelvis is given as a reason for an emergency caesarean without much evidence, as is 'cord around neck' given 1/3 of babies are born with their cord around their neck.

Childbearing hips I was 20 when I had my eldest ds. Straight up and down no good to speak of and I managed to squeeze the little bugger out at 10lb! Made my eyes water but we got the job done!

No hips lol not no good!

I was offered this in the ME. I said no way!
It used to be the done thing in the 1950's I think, and involves the doctor putting his fist up you as high as he can to 'guesstimate' how much your pelvis might widen. It's not an exactly science and doc said ' it will be VERY painful' I declined his kind offer.

It depends on size of hands, experience of doing it, experience of birth and then it's a guess anyway.

My midwife of 30 yrs experience told me my. Baby was tiny and I was all water. Baby was enormous - over 5 kg and would never have come out naturally:) Everyone is different.

Thank you for all the replies. I’m just trying to decide about an elective c section or whether to try natural. I know he’s looking big on scans, so I just wondered if I’d actually get him through my pelvis or not. His head is looking on the large side too.

My feet are a size 6 1/2, sometimes 7. And I’m 5’6. Size 18 so I’m fairly chunky (curvy!).

My midwife said between 2.5 - 4.5 kg is "normal" and over that they are cautious about size. I don't think measuring your pelvis is a thing they do tbh.

A lot of it is to do with babies positions as much as size. Mine have been drastically different in size (5lb9 and 8lb11) but both long pushing stages because they were back to back. Actually the bigger baby was much easier. I felt like gravity was really doing it's work there.

I know this might seem like a daft question but have you been speaking to a midwife or someone about your concerns? I know from your previous posts you have quite a bit of anxiety about the pregnancy as a whole, and I wonder what help your midwife might be able to give?

Another one whose mum was x rayed in the 80s here! I was premature and born by section so they measured her pelvis before allowing her a vbac with my brother... I suspect they no longer do this because xrays in pregnancy aren't recommended and by the sounds of it it can't be very accurate if your bones move during delivery! I think the baby's skull bones also flex at the joints so there's quite a lot of unknowns even if the baby is big?

Wish my mum had kept the xray though, it must look amazing!

Size 8 here with 35” hips and size 5 feet. Baby was 10lb9oz and back to back, and he did fit. We needed forceps, and I’d rather the next one be slightly smaller, but he did fit!

Are there other reasons behind you being offered the choice, and are you in the UK?

I only ask because as a general rule in the UK it is assumed and encouraged that you will have a vaginal birth unless there are other factors to consider that would lead to an elective c-section.

The vast majority of women have a pelvis that will accomodate a vaginal brth. I had an 8lb 11 oz baby, i was size 18 clothing, size 8 feet and she shot out with 2 pushes in 5 mins. Total labour time from stage 1 to birth of placenta was 4 and a half hours.

My mum was 5foot 4, size 5 feet and never more than 9 stone and had 4 babies, all very quick labours, barely making it to hospital for the 4th.

I'm 4' 11" and size 3 feet and my first was 10lb 8oz (at 38w)!

They didn't do any X-rays or anything like that but at an appointment late on in pregnancy they were pushing down on my belly (not painfully) to get a good outline (iykwim) of my DSs head. Much muttering ensued and other doctors were called in and this was repeated. More muttering and discussion and they all unanimously decided that there was no way my DS would fit out the regular way!

He had a massive head and it was just too big to engage in my pelvis.

I don't think they like to do invasive tests anymore or make a definiative decision early on so it really just a wait and see sort of thing. Things become clearer much closer to your due date.

My DS2 and then DS3 both arrived a month early yet were still too big to fit (we did try with my DS2 but it was just not possible).

My friend in Australia was scanned post failed natural labour and EMCS and told her pelvis was too small so should have sections in future but also that the scan was only accurate because she was just post birth and everything had stretched and relaxed as much as it ever would. I asked about it in this country and was told they don't do it.