identical or fraternal??

soontobess

At what point in your pregnancy with twins do you find out if the twins are identical or fraternal? I'm not pregnant with twins, but someone asked me today and I thought you guys would be the ones to ask!

tmp-303869625008161

The only way to know absolutely for certain is if you're having a boy and a girl. Identicals can have separate sacs and placentas just like fraternals.

Shockingly, there's a lot of misinformation about this even in the medical community. Some would say that the babies are for sure fraternal just because there are 2 sacs and placentas. I read, I can't remember where, that around 25% of identicals have separate placentas. So while it is more likely that 2 placentas would indicate fraternal twins, it's not an absolute.

hotfudgecustard

Others may have a better answer, but here's mine.  It's fairly easy to tell at whatever ultrasound shows if they are in one sac or two.  Ours was at 11 weeks.  There was clearly a line that was a membrane between the two babies.  There were two placentas as well.  That indicates two separate eggs were fertilized.  The babies are as genetically alike as our other two kids who were born separately.  Basically they are siblings who will be born on the same day. 

If there seems to be only one sac, that would indicate one egg that split which leads to identical twins.

(MoMs... is that accurate?)

lgurian

if twins are b/g they are def fraternal, after that no matter how many sacs/placentas you have to wait until you can do genetic testing. identicals can have their own sacs/placentas if the egg splits before it implants. although different sacs/placentas generally indicate a higher chance of fraternal.

soontobess

Thank you guys for the info!

franciscaz

If they are same sac it is for sure identical.  If it is separate sac and different gender it is for sure fraternal.  If it same gender seperate sac it could be either and needs a genetic test.

meldoo2002

Yes ours had 2 sacs, 2 placentas, and a good membrane between the 2 and after DNA testing we found out they are identical.

#6

We knew at 10wks when we found out it was twins.  My dr said there was one sac, one placenta so they were identical.  

jd0614

We found out they were identical at 10 weeks - they only had one placenta.  They didn't find the membrane until about 14 weeks. 

kiki408

I knew right away that my babies were identical because we did IVF, transfered two embies, and ended up with 3 pregnancies. The singleton didn't make it, but the twins in the same sack did. We knew right away one of my eggs had split. )

MandieSueM

We found out that two of our triplets were ID at the first u/s, which was at 5 1/2 weeks.  There were 2 sacs (just black spots at that time); one had 2 grains of rice in it and the other had 1.  It was confirmed at the 8 week u/s also.

macchiatto

hotfudgecustard:

Others may have a better answer, but here's mine.  It's fairly easy to tell at whatever ultrasound shows if they are in one sac or two.  Ours was at 11 weeks.  There was clearly a line that was a membrane between the two babies.  There were two placentas as well.  That indicates two separate eggs were fertilized.  The babies are as genetically alike as our other two kids who were born separately.  Basically they are siblings who will be born on the same day. 

If there seems to be only one sac, that would indicate one egg that split which leads to identical twins.

(MoMs... is that accurate?)

Actually, nope. About 10% of di-di twins are identical, so if they're the same sex, you'll have to wait till they're born to find out for sure. (If they look ID, get a genetic test done.)

BelleBaby

Boy/girl twins = fraternal (obviously)

If they're same sex, it's harder to tell.  Even identicals can have 2 sacs/2 placentas.  They can even look differently.  The only way to be 100% certain is a DNA test. 

In my case, the doctors are fairly certain their fraternal.  For one, they have 2 sacs/2 placentas.  My RE also said that it's more likely that both embies we put in during our IVF cycle took than one split into two and those implanted.