Identical/Fraternal ??

RoAnt05

I need help with some clarification.  I read somewhere that di/di twins have a 70% chance of being fraternal but it isn't unheard of for them to be identical.  I felt comfortable with this because it made sense in my mind.  But I keep seeing all of these people posting that their having fraternal twins because they are di/di.  I know that if they know the sex and they are boy/girl then obv. they are fraternal but how the heck do people know that they are def. fraternal just by knowing that they are di/di??  My guess is that they are misinformed, but I am open to being proven wrong just so I can understand this better

Mrs.Mezzy

The peri I see said that the only way to know fraternal twins for sure is if they are boy/girl and the only way to know ID for sure is if the are mono/mono.  So we are sure our girls are ID because they're mono/mono but otherwise you have to do genetic testing.

mommyof4boys

We were also told because of other things.  The line seperating the sacs looked "thicker" to them.  Granted we did IVF....but SIL and BIL have identicals and they had seperate sacs and a fused placenta but her line seperating her girls was very thin.  She also had TTTS starting around 20 weeks.  She was able to get to 36 weeks and days.  The girls were 5 pounds 7 ounces and 18inches 4 pounds 4 ounces 14 inches. 

RoAnt05

Mrs.Mezzy:

The peri I see said that the only way to know fraternal twins for sure is if they are boy/girl and the only way to know ID for sure is if the are mono/mono.  So we are sure our girls are ID because they're mono/mono but otherwise you have to do genetic testing.

ok this was pretty much how I had understood it.  I just feel like an idiot everytime people ask me if I know that they are frat. or ident and I say "well chances are that they may be fraternal but it isn't impossible that they may be identical..I guess we will see when they are born"

SCOOTER

If twins truly share a placenta, not fused, then they are identical too. Otherwise, you are right on the money.

jennnydawn

that was my case, we knew all along since my boys shared a placenta.  It was scary, because that put me at risk for TTS.

cands

If they are di-di they are more likely to be fraternal, but not certain.  If they are monochorionic or monoamniotic they are definetly identical.  If they are di-di the further apart they are implanted, the more likely they are to be fraternal. 

But there are other things people can know from early ultrasounds, for example, at 6 week ultrasound the tech was able to see the spots where I ovulated two eggs, which isn't 100% guarantee of fraternal, but it's pretty close, and combined with them being di-di and implanted on different sides, I told everyone they were fraternal, even before I was 100% sure (they have different eye colors, so I'm 100% sure now).

But the thing is that it really doesn't matter if they are identical or fraternal.  I'm still not 100% sure if my twin sister and I are identical or fraternal, and it just hadn't implacted our lives one way or another. 

lewis514

Mrs.Mezzy:

The peri I see said that the only way to know fraternal twins for sure is if they are boy/girl and the only way to know ID for sure is if the are mono/mono.  So we are sure our girls are ID because they're mono/mono but otherwise you have to do genetic testing.

 

This is the same thing my MFM told us. Our girls share a placenta but 2 sacs (membrane is very thin between them) so they told us they think they are identical but won't be able to tell until they are born.

sweater

All my peri's (yes...I had FOUR) told me you only know for sure if mono/mono or (god forbid) conjoined if they are ID. And you only know if fraternal if each baby has their own placenta.

Now of course di/di is USUALLY fraternal and di/mono is USUALLY identical...but there is definitely room for possibilites with fusing and all that jazz...

I totally understand all the confusion for MoMs. My kids being mono/mono and not even having an INCH between their cords on the placenta...and I still wondered if they were ID because they don't look identical (I know I know...they are starting to...)?

FeistyFille

I posted this in an above post too, but I've read that di/di twins could still be identical if the embryo split within 3 days of fertilization.  The chances are higher that they're fraternal, but they could still be identical.

My doc said that if it wasn't obvious with our boys at birth, they could examine (the word she used was "autopsy") the placenta to hopefully find out for sure.

Jen&John2005

SCOOTER:

If twins truly share a placenta, not fused, then they are identical too. Otherwise, you are right on the money.

Yep, my id twins share a placenta.  If the fertlized egg divides early enough, it is certainly possible to have di/di identical twins.  Mine are mono/di.  See https://www.baby2see.com/multiples/twins.html for a good explanation.

FaeryStarGazer

lewis514:

This is the same thing my MFM told us. Our girls share a placenta but 2 sacs (membrane is very thin between them) so they told us they think they are identical but won't be able to tell until they are born.

This was exactly our situation. One big placenta, very thin seperating membrane- they didn't even see it for a very long time! We got them tested for our own knowledge and they are identical.

mmbench

Obviously some doctors feel comforable making an assumption based on their best guess and the odds.  If the parents don't know a lot about twinning (and who would unless you're in that situation), why question it.

 Unless their B/G or mono/mono, there's no way to know for sure without a DNA test.  We've been told our girls are identical and had TTTS, but they don't look alike at all to me.  I just can't justify the money for a test right now.

courtneyaok

From what I understand, the only way to know is through genetic testing.