When can you see a seperating membrane?

I have a good friend that is also a surrogate. They did a transfer of 2 embryos and had their first ultrasound yesterday (she's about 7 weeks...maybe a couple days). They discovered that one of the embies SPLIT and now she is pregnant with TRIPLETS! :icon_eek: She said they couldn't see anything separating the twins yet and asked me when I could see my twins separated..but mine were frats and it was never an issue (and besides we didn't know about my twins until 17 weeks when they were clearly defined).

They are freaking out right now! Since her head is swimming, I told her I would come and ask you smart twin experts! How early can you see a separating membrane in ID twins (providing that there is one)?

Thanks!

 

I'm not sure about the answer to your question, but I can help with the id thing a little. Basically, they may never see a separating membrane if the embryo split after about day 8. There are 3 kinds of id twin pregnancies: dichorionic/diamniotic (di-di - meaning they have 2 placentas and 2 amniotic sacs), monochorionic/diamniotic (mono-di - meaning they share the same placenta but have separate amniotic sacs), and monochorionic/monoamniotic (mono-mono - meaning that they share the same placenta and the same amniotic sac). If the embryo splits early (usually before day 3) then they are di-di. If it splits sometime in the middle (usually between days 4 and 8 ) then they are mono-di. If it splits later on then they are usually mono-mono.

I may have had this issue with my IVF, too. The doctors are unsure at the moment because they missed a baby in my first ultrasound so we'll never know what happened, but there is a suspicion I originally had 3 at first: one fraternal and a set of identicals. We're now moving toward thinking that I have a set of fraternals but we may never really know.

Anyway, when we were at the height of a critical time recently (one of my twins was having problems) I was told that had I been pregnant with the comibnation your friend has, I would have been advised to reduce the identical twins due to the high risk of identical twin pregnancies, especially if the twins are mono-di or mono-mono. I know for myself, it would be extremely difficult to do this and I don't think I could.

The risks are high, though. The identical twins could have a high risk for problems if they share the same placenta, and those risks could threaten the fraternal baby, as well. The entire pregnancy could be threatened essentially. Likewise, reduction is also risky and could threaten the entire pregnancy, as well as cause damage to the survivor - and they may not find the right one(s) to reduce.

I think they should be able to see a separating membrane if there is one provided they use a really good ultrasound either now or extremely soon. If they want to have reduction as a possibility, the earlier they decide the better because ideally it should be done before 9 weeks.

Good luck to your friend and to the parents of the babies she's carrying. Might I add that I think it's a wonderful gift and sacrifice your friend is doing and I admire her for it.

 

We saw our separating membrane (though incredibly thin) at about 10 weeks if my memory serves me correctly. Good Luck to your friend, what an amazing thing she is doing!!

 

They saw mine at 11 weeks but it was hard to find.. it was much easier found at 15 weeks.

 

QUOTE(Lizzybo @ Mar 29 2008, 10:37 AM) [snapback]693991[/snapback]
I'm not sure about the answer to your question, but I can help with the id thing a little. Basically, they may never see a separating membrane if the embryo split after about day 8. There are 3 kinds of id twin pregnancies: dichorionic/diamniotic (di-di - meaning they have 2 placentas and 2 amniotic sacs), monochorionic/diamniotic (mono-di - meaning they share the same placenta but have separate amniotic sacs), and monochorionic/monoamniotic (mono-mono - meaning that they share the same placenta and the same amniotic sac). If the embryo splits early (usually before day 3) then they are di-di. If it splits sometime in the middle (usually between days 4 and 8 ) then they are mono-di. If it splits later on then they are usually mono-mono.

I may have had this issue with my IVF, too. The doctors are unsure at the moment because they missed a baby in my first ultrasound so we'll never know what happened, but there is a suspicion I originally had 3 at first: one fraternal and a set of identicals. We're now moving toward thinking that I have a set of fraternals but we may never really know.

Anyway, when we were at the height of a critical time recently (one of my twins was having problems) I was told that had I been pregnant with the comibnation your friend has, I would have been advised to reduce the identical twins due to the high risk of identical twin pregnancies, especially if the twins are mono-di or mono-mono. I know for myself, it would be extremely difficult to do this and I don't think I could.

The risks are high, though. The identical twins could have a high risk for problems if they share the same placenta, and those risks could threaten the fraternal baby, as well. The entire pregnancy could be threatened essentially. Likewise, reduction is also risky and could threaten the entire pregnancy, as well as cause damage to the survivor - and they may not find the right one(s) to reduce.

I think they should be able to see a separating membrane if there is one provided they use a really good ultrasound either now or extremely soon. If they want to have reduction as a possibility, the earlier they decide the better because ideally it should be done before 9 weeks.

Good luck to your friend and to the parents of the babies she's carrying. Might I add that I think it's a wonderful gift and sacrifice your friend is doing and I admire her for it.


Thanks for the science lesson! I have twins, but since they were not ID, I never really thought about all that is involved on that end. They definitely would have split after day 5...that's when 2 babes were transfered. And we also know that if they reduce the pregnancy, they will take the twins. They haven't decided yet.

Thanks for the info ladies!

 

I was worried I was being condescending and I didn't mean to be - I just didn't know how much you knew about id twins. I only just learned all of that stuff because it suddenly became crucial to my situation.

The neat thing about IVF is that they can keep the embryos under watch until day 3-5. I'm dying to ask an embriologist about the identical twin thing, mainly about what they have seen in their work.

I'll pray for your friend and the parents of the babies. I know this must be a very difficult time for them all.

 

The membrane is best seen between weeks 12-16. If it is thin, it will be hard to see early on. If your friend does indeed turn out to be carrying monoamniotic twins, tell her to check out monoamniotic.org. My twins were monoamniotic too. It is a great place to gather the lastest, most current information on this subject.

 

We didn't see ours until 16 weeks - and it was just for a second. Then we had trouble with TTTS, so we were always looking for that darn thing.

 

We were able to see our separating membrane at around 7-8 weeks and we only ever saw it at the peri's office (we never saw it on my ob's office u/s- which I had several of)... The chances of your friend having mo-mo twins is very rare- only 5-10% chance with id's, so the odds are definitely on her side! Even if they're mono/di (which is what my boys were- sharing the same placenta, but different amniotic sacs) there are more risks involved, like TTTS, but even then those odds are low. so again, the numbers are on her side... Good luck to her- what a great thing she is doing!!

 

QUOTE(Lizzybo @ Mar 30 2008, 09:56 AM) [snapback]694253[/snapback]
I was worried I was being condescending and I didn't mean to be - I just didn't know how much you knew about id twins. I only just learned all of that stuff because it suddenly became crucial to my situation.

The neat thing about IVF is that they can keep the embryos under watch until day 3-5. I'm dying to ask an embriologist about the identical twin thing, mainly about what they have seen in their work.

I'll pray for your friend and the parents of the babies. I know this must be a very difficult time for them all.



Does this mean an IVF embryo can't split until after day 3-5?

I've heard of woman making it to 24 weeks and finding a membrane then - so you should never give up hope on it. If you check out www.monoamniotic.org there is a really good welcome section outlining early ultrasounds.

I wanted to say about the risks as well - 85% of mono mono diagnoses are wrong and a membrane is found. Obviously because my girls are mono mono's I would say you need to seek another opinion if reduction is offered because they are mono's. With proper monitoring the chances of having a successful pregnancy are high.

Good luck to your friend

Good luck to your friend

 

My OB *thought* that she saw the membrane at 9 weeks...just a glimpse. Throughout the next 5-8 U/S, it was never seen and they searched very hard for it. I was probably 20+ weeks when there was another glimpse. If you have had the NT scans done before, then you know how difficult it is to get just the right angle on the back of the neck in order to get that measurement? This is even more touchy. The membrane moves in "waves" in response to movement.

As others have already said, there is lots of time and she certainly shouldn't give up hope of it being seen.

 

QUOTE(Jocasta @ Mar 29 2008, 07:55 PM) [snapback]694721[/snapback]
Does this mean an IVF embryo can't split until after day 3-5?


Well, that's why I'd love to see ask an embryologist about this. When I had my NT ultrasound the doctor told me that there is still a chance that our twins are identical, even if they were di-di and he said he's 80% sure they are di-di. So, I said that I thought you could only get di-di twins if the embryo split before day 3 and we transferred our embryos at day 3, so I thought our embryologist would have noticed a split. The doctor said, "are you sure they can see when it splits? And when exactly is the day 3 - is it 3 days after fertilization or 3 days after it becomes a blastocyst or 3 days after implantation?" I have no idea about that.

So, the upshot is that an IVF embryo can split before day 3-5, but I don't know when day 1 starts in terms of identical splitting. I also learned in my recent research (well, in asking a doctor) that identical twins are up to 20 times more likely to occur with IVF pregnancies than in sexual pregnancies.

In this case of the surrogate, I'm hoping that they can find the membrane in time for them to be able to make some educated decisions about the pregnancy. It really depends on the type of identicals they are - as everyone's said. My guess is that given they are IVF, I wouldn't be surprised if they are mono-di, but they also may very well be mo-mo. I also agree with Acosta, that if reduction is advised that they get a second opinion and weigh all of their options before making such a huge and hefty decision.

 

I find the whole splitting thing so fascinating. I'm not surprised that identical's happen with IVF more than the general population. Makes sense that the process somehow makes the embryo more unstable and more likely to split. According to http://en.wikipedia.org/wiki/Twin splitting happens X days after fertilization so maybe they can't see the split at that stage?