my mono/di twins turned into di/di twins

Hello, ladies. I just went to my 12 week u/s appointment. At 7 weeks, the u/s showed mono/mono twins. At 8.5 weeks, the u/s showed mono/di twins with a very obvious membrane and 1 placenta. At 12 weeks, u/s showed a very obvious membrane between them and a twin peak sign. The doctor thinks they are di/di twins. But isn't the earlier u/s more accurate? My husband and I still think they are mono/di twins because they are right next to each other. Has this happened to anyone else? Any advice/input is appreciated. Also baby B is 5 days behind baby A. The technician said their size difference is about 1mm. Should we be concerned about that? Thanks!

 

QUOTE(lilymoo @ Dec 10 2008, 12:58 PM) [snapback]1105500[/snapback]
Hello, ladies. I just went to my 12 week u/s appointment. At 7 weeks, the u/s showed mono/mono twins. At 8.5 weeks, the u/s showed mono/di twins with a very obvious membrane and 1 placenta. At 12 weeks, u/s showed a very obvious membrane between them and a twin peak sign. The doctor thinks they are di/di twins. But isn't the earlier u/s more accurate? My husband and I still think they are mono/di twins because they are right next to each other. Has this happened to anyone else? Any advice/input is appreciated. Also baby B is 5 days behind baby A. The technician said their size difference is about 1mm. Should we be concerned about that? Thanks!


I can't help you but was jsut wonderign what mono/di twins are?? IS that identical vs fraternal??

 

Can you scan in your early u/s pics and I'll tell you.

I think it's weird when they change their minds later on. If they were mono-di then they still are.

Let's see the pics!!

 

i would love to put the pictures up but i don't have a scanner.

QUOTE(sfried93 @ Dec 10 2008, 12:03 PM) [snapback]1105510[/snapback]
I can't help you but was jsut wonderign what mono/di twins are?? IS that identical vs fraternal??



MOno/di twins are identical. Di/di can be identical (30%) or fraternal (70%)

 

I'm not a lady but I'll tell you what when down with us... those estimates are more like guesses. My son stayed ahead of my daughter by 4-5 days for the whole pregnancy. The doc would measure, estimate weight, blah,blah,blah. My wife had a C at 36 weeks, and the day before he guessed they weighed 5 lbs. On birth day they both weighed 6 1/2 lbs.

 

When i found out i was having twins I was 7w3d. At that time they weren't able to tell me what kind they were, but they had me wait 3-4 weeks before going to the peri to find out what kind they were. So at 11w3d i found out that they were mono/di because they were lacking the twin peak.

I dont know about them waiting a longer period of time made the difference, maybe that is why they are able to see more at the later one???? Im not sure, but I think that it is hard to see the placenta early on, so maybe they did the u/s to early?

Sorry i don't think that im much help..

Maybe they are di/di but end up being identical and that is why they are so close together still

 

QUOTE(sfried93 @ Dec 10 2008, 10:03 AM) [snapback]1105510[/snapback]
I can't help you but was jsut wonderign what mono/di twins are?? IS that identical vs fraternal??

Mono/di refers to the # of amniotic sacs and placenta. So Mono=Monochorionic (1 placenta), Di=Diamniotic (2 amniotic sacs). Di/Di=2 placentas, 2 sacs, Mo/Mo=1 placenta, 1 sac. Does that make sense?

As for the OP, I don't really know the answer to your question. Sometimes it can really be hard to tell as there are a lot of different variables such as the technology of the machine used, the experience of the person doing the u/s etc.... It will be interesting to see what they say at your future appointments.

 

Sorry to hijack this thread but I'm actually having the same issue.

My OB deals with infertility all the time and I switched over to him after I got pregnant with twins since he deals with twins a lot. BUT he doesn't deal with mo/di twins a lot and he said based on these ultrasounds he can't whether they share a chorian/placenta or not. I can't tell about the placenta but it sure looks like they share a chorian. They for sure have separate amniotic sacs.

6 weeks 4 days
10 weeks 3 days

In response to your question, can they tell how many placentas there are now? The doctor thinks there are two?

 

When I went in last week I was 9 weeks and they said they didn't know whether they were identical or fraternal and didn't even mention mono or di??

 

QUOTE(lorin @ Dec 10 2008, 01:39 PM) [snapback]1105741[/snapback]
When I went in last week I was 9 weeks and they said they didn't know whether they were identical or fraternal and didn't even mention mono or di??


Mine didn't mention mono or di really either. I think some physicians figure the average layperson doesn't know the term anyway so they stick with identical/fraternal.

 

[SIZE=12pt]I am with lorin and beckylynn... we asked if he knew if they were identical or fraternal and he said it was really hard to tell at this stage and I was 11 weeks and 4 days when we had the first u/s done. My husband remembers him saying they were in 2 separate sacs though, most of the visit was a blur to me.. so much was going thru my head! He mentioned some of the lingo and I said is that all foreign?? He said it can be very confusing. I go back on the 22nd of this month.. I wonder if they will do another internal u/s? Do they usually do that stuff regularly? I feel at such a loss sometimes because I don't even know what I should be asking. My doctor said this would be his first set of twins ever!![/SIZE]

 

So if they are in two different sacs that means they are not identical correct??

 

QUOTE(lorin @ Dec 10 2008, 02:25 PM) [snapback]1105831[/snapback]
So if they are in two different sacs that means they are not identical correct??


If they are in different sacs that means they have a 30% chance of being identical and 70% chance of being fratenal. If they share the same sac, then they are 100% identical.

 

Not necessarily.
Identicals can be in seperate sacs too.
It's all confusing, I know.
The only REAL way to tell is if they are different sexes OR to have DNA done after birth.
Sorry.

 

QUOTE(lorin @ Dec 10 2008, 03:25 PM) [snapback]1105831[/snapback]
So if they are in two different sacs that means they are not identical correct??


Identical twins can also be in different sacs.

If they share a placenta, for sure they are ID (unless is two fused placentas which can mean both ID or fraternal).
If they each have a placenta, then they can be ID or Fraternal (30/70%) I believe.
This can easily determined by a DNA test at birth or anytime thereafter.
My children are Monochorionic (one placenta) Diamniotic (two sacs).

 

[SIZE=12pt]My doctor did tell me they could still be identical all depended on when the egg split if it was that case.. so I am trying to do research on everything! [/SIZE]

 

QUOTE(roadtocalvary @ Dec 10 2008, 03:32 PM) [snapback]1105848[/snapback]
[SIZE=12pt]My doctor did tell me they could still be identical all depended on when the egg split if it was that case.. so I am trying to do research on everything! [/SIZE]


Fraternals only come from two different eggs, hence the (1 placenta-1 sac)

If an egg splits, then they are 100 % identical. What the day of the splitting determines is the chorion/sacs issues

Here is a bit more info on ID (Italics is me)

Splitting of the embryo may occur at any time during the first 2 weeks after fertilization, resulting in several forms of MZT (monozygotic-1 egg). In about one third of the MZT cases, the splitting occurs within 72 hours of fertilization and the placenta will be dichorionic-diamniotic (i.e two placentae and two amniotic sacs). In about 2/3 of the MZT cases, the splitting occurs 4-8 days after fertilization, and the placenta will be monochorionic-diamniotic (i.e one placenta and two amniotic sacs). In 5% of the MZT cases, the splitting occurs 8-13 days after fertilization, resulting in monochorionic-monoamniotic twins (one placenta and one amniotic sac). Rarely, the splitting occurs after 13 days, resulting in conjoined twins.
SOURCE

Hope this helps! Is a bit confusing at first!

 

[SIZE=12pt]Maybe I didn't word that right.. I understand the identical and fraternal part..he just stated that ours were in 2 sacs but could still be identical, that we had to wait a little bit longer to find out.. that part I don't understand. Could be the machine he was using but I would think they would know right @11 weeks and 4 days?[/SIZE]

 

QUOTE(lorin @ Dec 10 2008, 12:25 PM) [snapback]1105831[/snapback]
So if they are in two different sacs that means they are not identical correct??

No, Mono/di (meaning they have 1 placenta and 2 sacs...I explained that above) twins are in 2 different sacs and are almost always identical. My girls are mono/di and are identical. Really the only 100% ways you can know for sure that they are identical or fraternal in utero is if, 1. You are having B/G twins (obviously fraternal), or 2. If you have Monoamniotic/Monochorionic (mo/mo) twins they are identical.

QUOTE(Carefulove @ Dec 10 2008, 12:39 PM) [snapback]1105868[/snapback]
Fraternals only come from two different eggs, hence the (1 placenta-1 sac)

Per Baby....Fraternals are typically Dichorionic/Diamniotic (2 Placentas and 2 sacs). Sometimes (rarely) the placenta can fuse together with fraternal twinning causing what looks like Mono/Di on u/s, and even some pathology reports after birth cannot differentiate 2 separate placentas.

 

Oooooh, I get it now!

 

QUOTE(roadtocalvary @ Dec 10 2008, 12:47 PM) [snapback]1105888[/snapback]
[SIZE=12pt]Maybe I didn't word that right.. I understand the identical and fraternal part..he just stated that ours were in 2 sacs but could still be identical, that we had to wait a little bit longer to find out.. that part I don't understand. Could be the machine he was using but I would think they would know right @11 weeks and 4 days?[/SIZE]

You will probably have to wait until they are born to find out. At which point if they have the different blood types they are definitely fraternal. If they have the same blood types you may have to do a DNA test.

 

Since there is a chance that they could be mono/di, that is the way the pregnancy should be treated. A mono/di pregnancy is more high risk than a di/di and needs to be monitored more carefully so you should err on the side of caution. Unless they babies end up being boy/girl (in which case they are obviously di/di ), you should get u/s at least every 2 weeks after 16 weeks to watch for TTTS.

QUOTE(lilymoo @ Dec 10 2008, 06:11 PM) [snapback]1105522[/snapback]
i would love to put the pictures up but i don't have a scanner.
MOno/di twins are identical. Di/di can be identical (30%) or fraternal (70%)



This a very easy statistic to get confused on. 30% of di/di twins are not identical. It's actually more like 15%. The 30% number comes from how many identical twins are di/di. Does that make sense?

If the twins are mono/di and diagnosed as such before 11 weeks then there is a very good chance they are identical. The reason I don't say it is 100% is because there could easily be a misdiagnosis and the only way to tell for sure if they are boy/girl, have different blood types, or if you have a DNA test.

Of IDENTICAL twins, you have about 1/3 that are di/di and 2/3 that are mono/di (with a tiny percentage that are mo/mo). Of ALL twins, you have about 1/3 that are identical and 2/3 that are fraternal. Here is a chart breakdown:

Fraternal = Di/Di Di/Di Di/Di
Fraternal = Di/Di Di/Di Di/Di
Identical = Di/Di Mo/Di Mo/Di


That means of every 9 twin pregnancies, you end up with 7 di/di twins and 2 mono/di twins. Since only one of those di/di sets of twins is identical, there is about a 15% chance of a set of di/di twins being identical. (I'm rounding numbers here and leaving out the mo/mo babies to keep things simple )

I'm not 100% positive of my math on this last one but I believe that if you find out your di/di babies are same sex though, your chances of them being identical shoot up to about 25%.

 

QUOTE(beckylynn @ Dec 10 2008, 03:32 PM) [snapback]1105730[/snapback]
Sorry to hijack this thread but I'm actually having the same issue.

My OB deals with infertility all the time and I switched over to him after I got pregnant with twins since he deals with twins a lot. BUT he doesn't deal with mo/di twins a lot and he said based on these ultrasounds he can't whether they share a chorian/placenta or not. I can't tell about the placenta but it sure looks like they share a chorian. They for sure have separate amniotic sacs.

6 weeks 4 days
10 weeks 3 days

In response to your question, can they tell how many placentas there are now? The doctor thinks there are two?



Those are HORRIBLE ultrasound photos!! No wonder he cannot tell LOL.

Yes. I'm going with mono di there tho. I need a better one of the earliest one. I see the yolk sac of the other baby in the same sac but I would prefer to be able to see both babies. Do you have a better one??

 

Here's the rough low down on the twin stats: and YES.. I could be wrong or off on them a bit.

70% of twins are fraternal twins
so the other 30% are identical twins

of THOSE 30% of identical twins, 30% are Di Di or have their own everything... that equates to a 9% chance TOTAL if you are having twins that they are di di identicals.

I know, it's confusing but if you said that your chances of having di di identicals was 30% that would be WAY HIGH!!!! Especially considering that 70% of twins are frats!! It's just not possible.

I hope I"m making sense!!

Also, it may be a bit higher considering the unreported di di ID's.. like Mary Kate and Ashley for instance (lol but just an example) because they 'think' they are fraternal..

 

I just wanted to give my two cents to the size question in the first post. My boys are di/di and were different in size almost from their first ultrasound on. At 10 weeks, the doc was a bit concerned b/c he said it was early to see such a big difference (almost 40% diff. on the growth scale), but since the little one was at 50% and the other one bigger, he said not to worry too much. By 23 weeks, they were at 500 and 600 grams (1.1lb vs. 1.3lb) but their organs/bones/heart rate/etc. looked great. So I would not worry too much, especially if they turn out to be di/di...

 

QUOTE(ivfbound078 @ Dec 10 2008, 06:55 PM) [snapback]1106268[/snapback]
Those are HORRIBLE ultrasound photos!! No wonder he cannot tell LOL.

Yes. I'm going with mono di there tho. I need a better one of the earliest one. I see the yolk sac of the other baby in the same sac but I would prefer to be able to see both babies. Do you have a better one??


That's the best we've got!! There are two yolk sacs that you can see and we COULD see both babies and heartbeats.

We do have individual photos of them at 6 weeks, that was the only one with them together.

Baby A - 6w4d
Baby B - 6w4d

Thanks for trying to help!

 

I (thought) I had it til I came to page 2...I need to do a little more study... :headbang:

 

QUOTE(beckylynn @ Dec 12 2008, 01:07 PM) [snapback]1108386[/snapback]
That's the best we've got!! There are two yolk sacs that you can see and we COULD see both babies and heartbeats.

We do have individual photos of them at 6 weeks, that was the only one with them together.

Baby A - 6w4d
Baby B - 6w4d

Thanks for trying to help!



Now those have got to be abdominal ultrasound pics from a REALLY old machine! They should not have been doing abdominal u/s on you that early on in pregnancy. Transvag u/s are MUCH more accurate.

I have only seen pics that bad when I was in for my "non ultrasound requiring appts" and they used the "Dinosaur u/s machine on me". That's what we ALL called it, it was funny! It's the old old one that they just use for fun purposes but certainly not for determining ANYTHING of any importance.

Tell me again where you got those?.. If that's all you've got I'd just say "I'm waiting til birth to DNA them." There's no way anyone will be able to determine anything from those.

Are you getting ultrasounds of better quality now?? I think you said those were from the old office, correct?

I'm soo sorry we cannot be of more help!! Congrats on your twins!!