Why would 2nd babies engage later?

[Emily]

Hi folks,

I've just been reading a pg book and came across
the statement (again) that 2nd and later babies
often don't engage until labor, while 1st babies
might engage 4+ weeks ahead. I find this puzzling...
It seems to me that everything would be looser
in 2nd & later pregnancies (pelvis, abdominal
muscles) and that all of those things would lead
2nd & later babies to engage *sooner* than 1st
babies. Does anyone know why it's the other way
around?

Emily
--
DS 5/02
EDD Labor Day 9/5/05

[KC]

Just me postulating, but perhaps because everything is stretched out
they can pop in and out of the pelvis in subsequent pgs. For me my
first 2 didn't engage until labor, and my 3rd engaged a few weeks
before, so who knows.

KC

[Jo]

KC wrote:
> Just me postulating, but perhaps because everything is stretched out
> they can pop in and out of the pelvis in subsequent pgs. For me my
> first 2 didn't engage until labor, and my 3rd engaged a few weeks
> before, so who knows.
>
> KC
>

Everything is looser later in pregnancy due to the release of relaxin
hormone. That's why in earlier pregnancy the head just doesn't
gravitate right down there from the start - the pelvic floor is
stronger. With a first baby, the abdominals are tighter and the uterus
hasn't been stretched before, so the baby has less room, and is forced
downwards sooner.

HTH :)

Jo (RM)

[Unadulterated Me]

Emily wrote:

> It seems to me that everything would be looser
> in 2nd & later pregnancies (pelvis, abdominal
> muscles) and that all of those things would lead
> 2nd & later babies to engage *sooner* than 1st
> babies. Does anyone know why it's the other way
> around?

It's 'because' things are looser that engagement happens later. Babies
need to flex their chins to their chest to engage the best part of their
head into the pelvis. This happens earlier in a first pregnancy because
the uterine and abdominal muscles are tighter and they squeeze the baby
into that position earlier. When things are less taunt and rigid the
positioning of the head into the pelvis happens later, when you tend to
have more weight on the baby, it has a heavier head and uterine
contractions increase to aid it.

Andrea

[Emily]

Unadulterated Me wrote:
> It's 'because' things are looser that engagement happens later. Babies
> need to flex their chins to their chest to engage the best part of their
> head into the pelvis. This happens earlier in a first pregnancy because
> the uterine and abdominal muscles are tighter and they squeeze the baby
> into that position earlier. When things are less taunt and rigid the
> positioning of the head into the pelvis happens later, when you tend to
> have more weight on the baby, it has a heavier head and uterine
> contractions increase to aid it.

Thanks -- that makes sense. I here I thought I was
carrying high because my abs were all extra strong or
something ;-P.

Emily

[Emily]

Jo wrote:
>
> Everything is looser later in pregnancy due to the release of relaxin
> hormone. That's why in earlier pregnancy the head just doesn't
> gravitate right down there from the start - the pelvic floor is
> stronger. With a first baby, the abdominals are tighter and the uterus
> hasn't been stretched before, so the baby has less room, and is forced
> downwards sooner.
>
> HTH :)

Thanks, Jo. It does!

Emily

[Welches]

"Unadulterated Me" > wrote in message
...
> Emily wrote:
>
>> It seems to me that everything would be looser
>> in 2nd & later pregnancies (pelvis, abdominal
>> muscles) and that all of those things would lead
>> 2nd & later babies to engage *sooner* than 1st
>> babies. Does anyone know why it's the other way
>> around?
>
> It's 'because' things are looser that engagement happens later. Babies
> need to flex their chins to their chest to engage the best part of their
> head into the pelvis. This happens earlier in a first pregnancy because
> the uterine and abdominal muscles are tighter and they squeeze the baby
> into that position earlier. When things are less taunt and rigid the
> positioning of the head into the pelvis happens later, when you tend to
> have more weight on the baby, it has a heavier head and uterine
> contractions increase to aid it.
>
I've obviously got brilliant muscles. #2 engaged by 28 weeks!
Well maybe not. ;-P
Debbie