Placenta Confusion

I posted before about my 12 week ultrasound, the sonographer said it looked like 1 placenta and 2 sacs. Now during my 20 week ultrasound I was told there are now 2 sacs and 2 placentas. I think they said one is in the front and one is in the back. I saw where the two placentas look like they meet.

I thought for awhile they are identical, but now I'm not so sure. I know they can be either fraternal or identical.
I know one placenta can't turn into two placentas. So was there 2 placentas all along and they fused before my 12 week ultrasound? The membrane between the babies is really thin, it was like that at my first ultrasound when I was 10 weeks.
Most of the ultrasound pictures I've seen with fraternal twins, there is a thick membrane between the babies and the identical twins show a very thin membrane between the two.

We thought the babies are two girls, but now we aren't real sure about that yet. Baby A is a girl definately, but Baby B isn't showing it's parts completely yet. So, of course if Baby B is a boy, then we know they are fraternal.

 

Good luck. I am no help but you are exactly right...one placenta is always identical. Two placentas that fused can be ID or frat. A thin membrane between them is USUALLY identical but not always. Congrats!!!

 

Sometimes when i had a US you couldnt even see the membrane. But when it was found it was thick. There was no second guessing what it was.

In the picture below.. you can hardly tell there is a membrane at all.. But there is because they are b/g twins.

 

This is pretty much exactly what I have just been told and its very confusing to me! I thought these things would be easier to tell. At 14 weeks, they thought they only saw one but with a thick membrane seperating them, but then at 18 and 22 they noted that they saw 2 sacs and 2 placentas. I know placentas can fuse, but it was very strange to me that one might have been missed before. Mine are both boys, so I guess I'll have to wait until after their born to find out for sure.

 

Again,
All you have to do is look at the 10 week ultrasound to see that they are identical and judging from that ultrasound, I am going to bet that there is ONE placenta and the tech or doc is incorrect. No, I'm not a Doctor but by looking at that 10 week ultrasound, it's clear to me that they are mono-di twins.. I'll be shocked if they aren't. Make sure they tell you after birth how many placentas there really are and if they were in the same sac.

I might be insane, but to me I think there is an amazingly definite difference between mono-di twins and di-di twins on ultrasound. It's not only the membrane, cuz at 10 weeks, we couldn't find mine.. it's the fact that they share a black "hole"... Di-Di twins have their own and it's very apparent at 10 weeks and earlier.. Just like yours. If someone could post a di-di ultrasound at 10 weeks so you could compare, I think the answer would be clear.

Also, the further along you are the more impossible it is to see if it's one or two placentas so I'm not sure why someone would change their mind NOW.

I'd bet the farm on them being mono-di.. I'm sticking with it. Let us know after they're born for sure

 

My OB said they were either fused or one at every u/s until I saw the peri at 19 weeks, who confirmed there were 2 very seperate placentas in very different places, and my twins were boy/girl anyway so definitely she is right. So my OB just was not seeing the other one.
Also the membrane on my u/s pic at 11 weeks(my first) was very thick, meaning most likely di/di also.

Ya never know. A tech should know for sure, or if they are b/g you will know.

 

QUOTE(momof5 @ Sep 27 2008, 09:48 PM) [snapback]1001094[/snapback]
Good luck. I am no help but you are exactly right...one placenta is always identical. Two placentas that fused can be ID or frat. A thin membrane between them is USUALLY identical but not always. Congrats!!!


Thank you. It's just frustrating when you're told one thing and then something else later. It doesn't matter what they are, I just want them to be healthy.

 

QUOTE(Ash Twins @ Sep 27 2008, 09:55 PM) [snapback]1001102[/snapback]
Sometimes when i had a US you couldnt even see the membrane. But when it was found it was thick. There was no second guessing what it was.

In the picture below.. you can hardly tell there is a membrane at all.. But there is because they are b/g twins.


I see what you mean on your sonogram. I could hardly see the membrane in any of my sonograms. The first one was at 10 weeks and the last one was at 20 weeks, it was there, but it wasn't very visable and it was never thick at any time that I saw it.
We saw it on a 3D ultrasound, it sure looks a lot different than on the regular sonograms. We found out that Baby A is a girl and Baby B keeps hiding it's private area so we haven't established a gender on this one yet.

 

QUOTE(Soon to be Mom of 4 @ Sep 29 2008, 03:01 PM) [snapback]1003612[/snapback]
I see what you mean on your sonogram. I could hardly see the membrane in any of my sonograms. The first one was at 10 weeks and the last one was at 20 weeks, it was there, but it wasn't very visable and it was never thick at any time that I saw it.
We saw it on a 3D ultrasound, it sure looks a lot different than on the regular sonograms. We found out that Baby A is a girl and Baby B keeps hiding it's private area so we haven't established a gender on this one yet.

I wish i had another US to show. But I didnt find out it was twins until 17.5 weeks. From what i have seen from US's off this site is: Di/di are mainly 2 "black holes" with a peanut inside. Mo/di or Mo/mo is one back hole with 2 peanuts inside.

Your US looks like one black hole with 2 peanuts inside. Some US techs and DR's just dont know aht they are looking at. One US dr told me that i had one placenta.. <_< and thats after i was told it was b/g..

ETA: I found this: http://pregnancy.about.com/cs/ultrasounds/l/blus0310b.htm These twins are def DI/DI.. There is a space between them. Enjoy!

 

I agree with ivfbound - yours are mo/di sharing a placenta. just make sure you are monitored frequently for TTTS - especially until 26-28 weeks. Your fluid levels ok? Everything else looks ok?

I kept getting different stories all over the place. If i only knew then what I know now.

You have two girls in there. I'd bet the farm on that too.

 

QUOTE(Yusra @ Sep 27 2008, 11:19 PM) [snapback]1001134[/snapback]
This is pretty much exactly what I have just been told and its very confusing to me! I thought these things would be easier to tell. At 14 weeks, they thought they only saw one but with a thick membrane seperating them, but then at 18 and 22 they noted that they saw 2 sacs and 2 placentas. I know placentas can fuse, but it was very strange to me that one might have been missed before. Mine are both boys, so I guess I'll have to wait until after their born to find out for sure.


I was really confused when they told me later that there are two placentas, it doesn't make sense.
My babies membrane is very thin. I bet there is only one placenta.
Congratulations on your twin boys. :woohoo:

 

QUOTE(jordynsmama+2 @ Sep 28 2008, 10:32 PM) [snapback]1002328[/snapback]
My OB said they were either fused or one at every u/s until I saw the peri at 19 weeks, who confirmed there were 2 very seperate placentas in very different places, and my twins were boy/girl anyway so definitely she is right. So my OB just was not seeing the other one.
Also the membrane on my u/s pic at 11 weeks(my first) was very thick, meaning most likely di/di also.

Ya never know. A tech should know for sure, or if they are b/g you will know.


The technician at my 12 week scan said he only saw one placenta and then the technician at my 20 week scan said she saw two placentas! I don't really believe it. The membrane between my babies was thin even at my first u/s at 10 weeks, it looked like a wispy piece of spider web! It was so thin, it was not even visible at all times. At my 12 week u/s the technician had to really search hard to get a good picture of the membrane.

Congratulations on your twin pregnancy and all the best to you and your family. :yahoo:

Thanks for the information.

 

Okay, this is probably not going to help your confusion, but I feel the need to share. Your u/s pics look just like mine. The placenta is all over the place. Throughout my pregnancy every u/s tech, dr., peri said I had one placenta. We were being monitored for TTTS. At birth the placenta was examined and it was two fused together. My entire pregnancy I thought I was having identicals and now we don't know. You won't know for sure either until your placenta is examined. Try not to drive yourself crazy wondering, but always ask the u/s tech what they think. Make sure your docs treat it as one placenta since there is a lot more to worry about. I hope you find out the sex of the other baby to help ease your mind a little. Hugs!

 

QUOTE(ferfischer @ Sep 29 2008, 07:23 PM) [snapback]1004131[/snapback]
I agree with ivfbound - yours are mo/di sharing a placenta. just make sure you are monitored frequently for TTTS - especially until 26-28 weeks. Your fluid levels ok? Everything else looks ok?

I kept getting different stories all over the place. If i only knew then what I know now.

You have two girls in there. I'd bet the farm on that too.


I think so too. I just don't see how there can be two placentas with such a thin membrane. I've seen so many ultrasounds and so far the thicker membranes were di/di and the very thin ones were mo/di.
All my fluid levels are great and everything looks really good. Thank you so much.

 

I'm not an expert and didn't see the u/s pictures but I'd guess the placentas were close together at the beginning and have just grown apart as the uterus expanded. They may have looked like a single placenta but no longer do. I'd guess that is pretty uncommon though because u/s before 11 weeks usually is a good indicator of one placenta versus two.

Also, a lot of people like to talk about membrane thickness as a way to determine identical v. fraternal but it's not a good indicator. That's why people who may have 1 placenta are so closely monitored even though it could actually be 2 placentas that are fused. The doctors can guess whether the pregnancy is mono or dichorionic but they can't be sure. There are very few ways to tell if a twin pregnancy is fraternal v identical after 11 weeks.

Since there is the chance that you could have one placenta I would still make sure you are receiving your u/s at least every 2 weeks to watch for TTTS.

ETA: I wrote this before reading the pp so I'm not referring to anyone in particular.

 

QUOTE(mommymeg @ Sep 30 2008, 03:11 AM) [snapback]1004376[/snapback]
Okay, this is probably not going to help your confusion, but I feel the need to share. Your u/s pics look just like mine. The placenta is all over the place. Throughout my pregnancy every u/s tech, dr., peri said I had one placenta. We were being monitored for TTTS. At birth the placenta was examined and it was two fused together. My entire pregnancy I thought I was having identicals and now we don't know. You won't know for sure either until your placenta is examined. Try not to drive yourself crazy wondering, but always ask the u/s tech what they think. Make sure your docs treat it as one placenta since there is a lot more to worry about. I hope you find out the sex of the other baby to help ease your mind a little. Hugs!


Thank you for the information.
Have you considered DNA? I think I will do that if I have two girls (one is a girl for sure).
I just want to make sure everything goes well for them. I have an OB appointment tomorrow, so we get to
check on them again. :yahoo:

Thanks again.

 

I'm totally trying to get Meg to get her boys DNA tested - i think they want to though! I really can't tell if they are ID or not!

But, based on your 10 week u/s, which i saw before, yours are mo/di. you have two girls in there!

 

QUOTE(Ali M @ Sep 30 2008, 11:41 PM) [snapback]1006151[/snapback]
I'm not an expert and didn't see the u/s pictures but I'd guess the placentas were close together at the beginning and have just grown apart as the uterus expanded. They may have looked like a single placenta but no longer do. I'd guess that is pretty uncommon though because u/s before 11 weeks usually is a good indicator of one placenta versus two.

Also, a lot of people like to talk about membrane thickness as a way to determine identical v. fraternal but it's not a good indicator. That's why people who may have 1 placenta are so closely monitored even though it could actually be 2 placentas that are fused. The doctors can guess whether the pregnancy is mono or dichorionic but they can't be sure. There are very few ways to tell if a twin pregnancy is fraternal v identical after 11 weeks.

Since there is the chance that you could have one placenta I would still make sure you are receiving your u/s at least every 2 weeks to watch for TTTS.

ETA: I wrote this before reading the pp so I'm not referring to anyone in particular.


I'll be having another ultrasound in 3 weeks, I'll ask about it then to make sure they are seeing two. I just had one today with my OB, but all he does is check fluid levels, heartbeats etc., everything looked good. He said starting now I will be seeing him every two weeks.
I've read about the membrane thickness and I'm under the impression that the thinner it is with no lambda sign, that it would indicate 1 chorion, which I assume means one placenta. But, I could be wrong in my way of thinking.

Thank you for the information, I appreciate it greatly.
I put links to the u/s pictures below.

10 Weeks
http://i538.photobucket.com/albums/ff342/k...trasound3-2.jpg
12 Weeks
http://i538.photobucket.com/albums/ff342/k...ns8-06-08-1.jpg