Thin membrane and identical twins?

I got my big U/S report back today at my 21 week appointment.

Well, both the doctor and nurse said the membrane was super thin, so they were almost 100% positive it's identical twins.

How can they be so sure just by that? I remember when I found out it was twins that they mentioned there were two placenta's. How can they be so certain they're identical?

Both boys are measuring only 2 days apart and exactly the same length! They're already a lot alike, LOL!

Anyway, I'm very excited!

 

I should add that I took 50 mg of clomid to conceive, so I thought for sure they were fraternal. The doctor still says that you can have identical twins even if you take clomid. It's just a wonderful freak of nature. That really takes me by surprise.

I guess in my case, I have to wait clear until the babies are born to do testing, lol! I wish there was a way to know for sure right now. LOL!

 

I do think that one can only tell for sure after the babies are born. Professional guessing I think!!

 

The dr. said the same thing to me only the other way around he said the membrane seperating them was so thick he said I was having faternals

 

QUOTE(Boni @ Apr 3 2008, 07:03 AM) [snapback]702317[/snapback]
I do think that one can only tell for sure after the babies are born. Professional guessing I think!!


Agreed.

 

Congrats on your twins!!
Keep in mind that if the egg separates between day 1 and 3, the babies share nothing, so they can have their own placentas.
My girls are identical and shared nothing.

I'm sure you will be excited to see how they are when they are born!! Keep in mind though, that the environment inside you adds to the shaping of their heads and faces, so just because one has a round face and the other oval, does not mean they are not identical!

Have fun!!

 

QUOTE(cvaughn @ Apr 3 2008, 07:05 AM) [snapback]702359[/snapback]
The dr. said the same thing to me only the other way around he said the membrane seperating them was so thick he said I was having faternals


Bologna. Sorry, but it drives me CRAZY when I read about a doc who says something like this. T&T had their own placentas and implanted as far apart as possible so there wasn't any fusing going on to muddle things. They are identical. If the egg splits in the first 3 days, you get identical twins with their own placentas. As my guys so clearly demonstrated, they can drift a bit before finding a spot to land so implantation site isn't a good indicator either. Until they're found to be b/g, have different blood types, or have genetic traits that don't match, you won't know that they're fraternal and neither will your doctor.

As for the membrane thing... I think it's pretty much a guess at 21 weeks. The membrane was so "thin" at our 20 week ultrasound that it was a barely visible flicker as the two of them kicked the heck out of each other but we already knew from the previous ultrasound that there were 4 layers there.

 

The only real way you know if they're fraternals is if it is a boy and a girl. Other than that, you just have to wait it out and see one they're born.

 

My sister's twins had their own placentas but the same blood type. She had them tested and they're identical.

 

QUOTE(Mairoge @ Apr 3 2008, 09:45 AM) [snapback]702523[/snapback]
The only real way you know if they're fraternals is if it is a boy and a girl. Other than that, you just have to wait it out and see one they're born.


Another way to know if they're fraternal is if they have different blood types...

 

Thanks for all your replies.

I am just a bit confused because this doctor has delivered TONS of twins and is highly respectable and knowledgeable. His nurse is right up there with him and she noted the same thing that they were most likely identicals. (She's an identical twin herself, lol!!!)

I know it's not 100% until I have the testing done after they're born though. It was awesome to hear both of them say they're almost 100% sure they're identical. He drew out how mine were and everthing, but it is all sooo confusing to me. I just remember heairng very, very thin membrane, that's about it...gosh it's going to be a long wait for the testing, lol! Apparently they test the placenta when they're born? Interesting!

 

QUOTE(2blessed @ Apr 3 2008, 07:23 AM) [snapback]702461[/snapback]
Congrats on your twins!!
Keep in mind that if the egg separates between day 1 and 3, the babies share nothing, so they can have their own placentas.
My girls are identical and shared nothing.

I'm sure you will be excited to see how they are when they are born!! Keep in mind though, that the environment inside you adds to the shaping of their heads and faces, so just because one has a round face and the other oval, does not mean they are not identical!

Have fun!!



I completly agree with this. They told me all through my pregnancy that my girls were identical, but when the results came back from the placenta they said that they were di di. They had the same blood type and looked so much alike that I had them tested and they are identical. My girls have diffrent shaped heads totally and it makes them look different most of the time. ONes head is longer and one is shorter. Good luck with your babies.

 

You know Lisa.. I was really wondering about the Tech when she said she swore they were fraternal. There is NO way of knowing fraternal or identical with di di twins.. and if I remember right your first u/s confirmed di/di..which is wonderful in itsself.. least risky.. but there is still like a 30% chance di/di twins are identical. In your case I don't think anyone is going to be able to tell you until those little men are here.

I was told mine are identical because at our first u/s they saw 1 chorion sac.. and 1 placenta and found a very thin (I never remember seeing it) septum. At 15 weeks it took a while but they found the septum again.. its super super hairline thin and any movement from the babies would make it vanish.. this also was true at my 20 week u/s.. the Tech had a really hard time getting a good picture because it kept disappearing. She said we know its there so its not worrisome.. they just like good pictures of it.

Maybe at our next u/s's we should ask for a picture of it..

 

Now I'm really questioning my understanding.

I'm 11 weeks pregnant with twins -- they share what the doctor called a "pregnancy sac", and have seperate amniotic sacs.

He didn't use the terminology, but I thought that meant I have mono/di identicals.

They have to be identical if they share that sac, right?

We did IVF with two embryos transferred back, and saw two sacs previously with heartbeats, but one is now empty.
We can still see that empty sac on the sonogram, and both babies we have now are in the same sac and now we see two heartbeats in that sac.
So we had three, lost one, and I'm all confused about the terminology.

This thread talks about how thin the membrane separating them being used to guess if they're fraternal or not, but I thought in the same sac meant identical?

Thanks in advance,

 

I didn't know I was having twins until 22 weeks. They were diagnosed as mo/di identicals with a VERY thin dividing membrane. The peri had such a hard time finding the membrane that she was concerned that they were actually mo/mo. We were skeptical because I have a family history of fraternal twins. But we believed the doctors and went with the idea that they were identical. They were born looking very similar and the OB said the placenta looked like such one. But within a few hours we were convinced they were fraternal. They just looked soooooo different, even though they had the same hair and eye color. Low and behold, they have different blood types and are very clearly fraternal.

There is no way to know now. It's too late into the pregnancy to accurately diagnosis mo/di twins. I hate to tell you but you'll just have to wait.

 

Thanks so much for the information. I cannot believe how confusing it can get. Especially when you have your nurse tell you at one appointment at 17 weeks with an u/s that she thinks they're identical and then your doctor who's dealt with SO many twin pregnancies explain that he also thinks they are identical. There were TWO placentas, so maybe it was a mistake and they somehow just missed that. But it's kind of funny that both of them think they're identical!!! LOL!!! I will be callingt them tomorrow for a more detailed explanation. I hope to get some more answers as to why they think they are identical. I think it's just a simple mistake, that they just didn't realise there were two placentas.

 

Now that I think of it, I am remembering him saying there was 1 membrane....not 4 like a di/di would have. Hmm, but there are two placentas. LOL!!! I think I'm driving myself nuts. I know there is no sure fire way of knowing 100% if they're identical or fraternal at this point, but this is so interesting to me, and has my curiousity going!!! LOL

 

Makes you want to go a little crazy doesn't it..lol. sounds like maybe they are monochorionic/diamniotic.. but have their own placenta. I do believe that is possible.