what are the latest theories on why/when we go into labor?

Is it because the uterus can no longer expand any further? Are their any credible theories out there?

Thanks.

 

From what I understand is that when your uterus reaches the size of a woman pregnant with a singleton who is 40weeks, the uterus signals the rest of the body that it's time to deliver. The problem with twin and multiple pregnancies is that your uterus reaches the 40 week size much earlier, therefore so many twin and multiples pregnancies have problems with pre-term labor and end up delivering early. I delivered at 34 weeks and I definitely looked 9mos. pregnant.

 

wow. i didn't know that. very interesting!

 

QUOTE(TAD665 @ Jul 21 2007, 09:21 PM) [snapback]340239[/snapback]
From what I understand is that when your uterus reaches the size of a woman pregnant with a singleton who is 40weeks, the uterus signals the rest of the body that it's time to deliver. The problem with twin and multiple pregnancies is that your uterus reaches the 40 week size much earlier, therefore so many twin and multiples pregnancies have problems with pre-term labor and end up delivering early. I delivered at 34 weeks and I definitely looked 9mos. pregnant.


I had never heard that, but that makes a lot of sense. I was measuring about 42+ weeks around the time I went into labor with the twins. Hmmm, thanks for sharing that.

 

QUOTE(RondaJo @ Jul 21 2007, 10:33 PM) [snapback]340291[/snapback]
I had never heard that, but that makes a lot of sense. I was measuring about 42+ weeks around the time I went into labor with the twins. Hmmm, thanks for sharing that.



I never heard that either. I'll be measuring 40 weeks at my next appointment in two weeks ...but I'll only be 32 weeks. I hope I don't start labor because of that.

 

QUOTE(TAD665 @ Jul 21 2007, 10:21 PM) [snapback]340239[/snapback]
From what I understand is that when your uterus reaches the size of a woman pregnant with a singleton who is 40weeks, the uterus signals the rest of the body that it's time to deliver. The problem with twin and multiple pregnancies is that your uterus reaches the 40 week size much earlier, therefore so many twin and multiples pregnancies have problems with pre-term labor and end up delivering early. I delivered at 34 weeks and I definitely looked 9mos. pregnant.



From what I've been told, its not so much that its the size of any woman, but the size YOUR uterus will be at 40 weeks. Just throwing in that if you are measuring big, dont panic, its normal!! Your 40 weeks uterus size could be another woman's 46 weeks. If that makes sense at all...Thats why women who have had children before have a better chance of carrying fartherthan a first time mother... My sources may be wrong... but it kinda makes sense to me....
Shannon

 

It's an interesting question... All I know is I was measuring 42 wks when I was only 31wks along and I haven't gone into labor yet. This is also my first pregnancy. It's probably different for everyone.

 

My OB told me the same thing as the previous poster mentioned. He said my uterus simply couldn't stretch anymore and my body thought it was time to go into labor. But- at 28 weeks he said I was the same size I was with my singleton at 39 weeks (when he was born) and my water didn't break with the girls until 33 weeks. I think most people have a little extra stretch in them, you just won't know how much until you get there.

 

I've heard the theory that you go into labor when your uterus reaches the equivalent of 40 weeks but I do not believe that is true. There are several people, including on this site, that have gone to 37-40 weeks with their twin pregnancy with fundal measurements in the 50+s. I measured right on schedule at 41cm and 41 weeks with my singleton and had the twins a few days short of 39 weeks and we had stopped measuring many weeks earlier when I was at 50cm.

They are still not sure of the real reasons that people go into labor. They would be better able to prevent preterm labor if they knew that actual reasons.

It is interesting stuff though.

 

I have heard that too, about your body going in to labour when your uterus reaches the forty wk mark.

I have two children that were born at 38wks both weighing 6pound 7 and a half ounces.

I am freaking a little...does this mean i will go into labour when my babies reach a combined weight of say 7pound? That would be about 3 and a half pound each???

One of my good friends had identical twins and is a similar size to me , petite, and she went into labour at 27 weeks . Babies were 5pound and 3 pound.

Has anyone else given birth early to twins with a comnined weight of a previous baby?

How often do women have really healthy 6 and 7 pound each twin babies?

 

Natasha, I am already carrying one pound more of baby than when my singleton was born. I have seen many women with twins measuring way more than 40 weeks and continue to carry just fine.

I've also heard that there is a horomone that they babies release when they are done and that triggers labor. Anyone know about that?

 

I measured 38 weeks when I was just 34 weeks pregnant when I delivered.

 

I've heard both the above mentioned theories. I think it depends on when nature of our bodies that decides when they are suppose to be here. Both of my children were delivered 3 days past their date. DD was 5 lbs 11 oz, and DS was 7 lbs 11 oz.

 

This is complete hearsay.....its a combination of factors thus the numerous ways to try and stop labor. One the body will release a hormone (resulting in ffn tests being performed) as to why the body releases this hormone I have read mixed results. One side of the fence indicates the body/uterus reaches a point of maximum growth and begins stressing the body thus triggers the release. This explains why some doctors are so adamant about bed rest, etc...because they don't want the body stressed. The other side of the fences prescribes the babies trigger the release of the hormone due to growth maximum in the uterus. Whether this is due to space, vessel deterioration or degeneration of the uterine cavity or a combination is largely undecided. Personally, I feel it is a mix of all the above and agree with pp that one woman's 40 weeks is not the same as another's despite that little measuring tape.

 

I am measuring 47 weeks.. and i am carrying double the weight of my singleton.. I have about 13 lbs of babies in me..

For me i think the babies come when they are ready.. not when my body is.. URGG..

 

I've heard that no one know for sure - I pasted a quote below that I've read. I don't think that it's size alone; I measured 44 weeks with my 9.5 lb daughter and still didn't go into labor on my own!

"Toward the end of pregnancy, the uterus reaches maximum size, the placenta begins to age, and the level of the hormone progesterone begins to drop. Your body becomes more sensitive to the chemical oxytocin, which triggers labor contractions. Finally, the baby itself may release prostaglandins that trigger labor."

 

I am on board with the "combination of factors" theory. DH is a FP MD, and basically told me there is no way to tell when ANYONE will go into labor, singleton or multiple. Do/ did you smoke within the last 2 years? Same for drugs & alcohol? Genetic factors that may cause early, long or delayed labor? (This could be partly hormonal inheritance). Diet? Hydration level? General health for the year before conception and throughout the pregnancy? The list goes on and on... and everyone is different.

My first pregnancy was DS, born 1 day before 40 weeks, and was 10 lbs. 1 oz :icon_eek: , no gestetional diabetes, and U/S-ed at 8 pounds or so just a week before delivery. I was in labor almost 3 days and ended up with an emergency C/S because I got a fever and did not progress. :crazy:

When I found out at almost 21 weeks that we were having twins the 2nd pregnancy, I guessed since I am healthy in general that I could carry up to maybe 25% more than DS #1... TOTAL GUESS. Turned out to be right about there though... twins' birth stats are below. But with them, my water broke at 35.2. And I know I measured WAAAAAAAAAY over 40 weeks. (Is there an alien- belly icon?) But my dr.'s would not tell me how much. But I do know I popped a button on my 8- month maternity blouse when I was 21 weeks with the twins... They did not want me to benchmark that way. They said fundal height was a completely different ball of wax in a multiple pregnancy than singleton. Sorry this got long... HTH

 

QUOTE
I have two children that were born at 38wks both weighing 6pound 7 and a half ounces.

I am freaking a little...does this mean i will go into labour when my babies reach a combined weight of say 7pound? That would be about 3 and a half pound each???


I wouldn't think so no. My guys were a combined weight of over 11 pounds plus all the afterbirth, and the one I am carrying now is est. to be at nearly 6 lbs.

I agree with PP, it probably just happens for a mixed reason of factors... and since I am a spiritual person I think God's reasoning has a lot to do with it as well.

 

QUOTE(AshleyLD @ Aug 24 2007, 12:24 PM) [snapback]378565[/snapback]
I am measuring 47 weeks.. and i am carrying double the weight of my singleton.. I have about 13 lbs of babies in me..

For me i think the babies come when they are ready.. not when my body is.. URGG..


I totally agree with you on this one. I'm also measuring at 47wks and haven't gone into labor yet, obviously. As for the other comments on being able to carry twins longer when you've had previous pregnancies, I'm not sure that's completely accurate. I have seen many first time moms carry twins for 36 wks if not longer. This is my first pregnancy and I'm at 36 wks. Every woman's body is so different, it's hard to say for sure who carries the longest/shortest. It's a great topic of discussion though

 

QUOTE(girls! @ Aug 24 2007, 06:50 AM) [snapback]378070[/snapback]
I've also heard that there is a horomone that they babies release when they are done and that triggers labor. Anyone know about that?


That is what I have heard as well. The baby will release a hormone that will start to stretch the cervix, releasing yet another hormone causing a contraction. The contraction pushes the baby down the canal towards the cervix causing more hormones to release in effect causing more contractions. That is with one baby. My guess is with two babies that labor will start with the stretching of the cervix (once the uterus can no longer stretch anymore) releasing the hormones to cause contractions.

 

QUOTE(AshleyLD @ Aug 24 2007, 05:24 PM) [snapback]378565[/snapback]
For me i think the babies come when they are ready.. not when my body is.. URGG..


Gotta disagree there - if babies came when they were ready, there wouldn't be any NICUs.

 

QUOTE(betseeee @ Aug 24 2007, 03:35 PM) [snapback]379022[/snapback]
For me i think the babies come when they are ready.. not when my body is.. URGG..

Gotta disagree there - if babies came when they were ready, there wouldn't be any NICUs.


This is why i said for me.. I wouldnt say that for everyone because as you said, then there wouldnt be any NICU times.