Identical or fraternal?

kateryna72

How and when did you find out if your kids were identical or fraternal? I'm 17 weeks pregnant, and my friends & family keep asking me if my twins are identical or fraternal. I keep telling everyone they're probably fraternal since they're in separate sacs & fraternal twins run in my family, but honestly it hasn't come up with the doctor yet and it just hadn't occurred to me to ask.

blairdavis99

I'm probably not much help but I found out at 18 weeks when they told me one was a boy & one was a girl

ash8684113

Boy girl twins are always fraternal. Otherwise you cannot tell until they are born at the earliest. Most people think that if they are didi twins with separate sacs and placentas they are automatically fraternal but that is not true, more like 70% chance they Are. It all depends on when the egg potentially splits or if there are actually 2 separate eggs.

I'm 27 weeks with didi boys and people ask me constantly so I just tell them we won't know till they are born. If they look similar at birth you can have dna testing and that's the only way to know for sure if same sex twins are identical or fraternal.

SisterMaryNapalm

ash8684113 said:

Boy girl twins are always fraternal. Otherwise you cannot tell until they are born at the earliest. Most people think that if they are didi twins with separate sacs and placentas they are automatically fraternal but that is not true, more like 70% chance they Are. It all depends on when the egg potentially splits or if there are actually 2 separate eggs.

I'm 27 weeks with didi boys and people ask me constantly so I just tell them we won't know till they are born. If they look similar at birth you can have dna testing and that's the only way to know for sure if same sex twins are identical or fraternal.

I found this helpful, thank you

kateryna72

Okay, thanks! That's what I thought! My cousin just told me yesterday that her friend is pregnant with twins and somehow already knows that they are identical, but I was kind of skeptical because I was under the impression that they can't confirm identical twins until the dna test after they're born.

Kagemi

I'm pretty sure that if the babies share a placenta they are always identical.  It's only when they have separate placentas they can be fraternal or identical.

jdllace

Kagemi said:

I'm pretty sure that if the babies share a placenta they are always identical.  It's only when they have separate placentas they can be fraternal or identical.

This is correct. If they're sharing a placenta that automatically makes them identical since you know the egg split. So since this is the case with me I already know they're identical and will either be b/b or g/g. If they're di-di (separate sacs) and the same sex you'd have to wait for a DNA test after they're born.

chickaboo1974

jdllace said:

I'm pretty sure that if the babies share a placenta they are always identical.  It's only when they have separate placentas they can be fraternal or identical.

This is correct. If they're sharing a placenta that automatically makes them identical since you know the egg split. So since this is the case with me I already know they're identical and will either be b/b or g/g. If they're di-di (separate sacs) and the same sex you'd have to wait for a DNA test after they're born.

 A DNA test is not always needed.  My boys were di-di and I could tell right away (in photos since I was not allowed to go see them in the NICU) they were fraternal. They had very different shapes of their heads/faces, and their features were very different.

jdllace

Many times babies have a different shaped head especially in the beginning because of how they were positioned in the womb. I have a friend who swore up and down her boys had to be fraternal but the DNA test came back identical.

MrsCaseyK

Same placenta could be an instance where the placentas grew together too. So not a fool proof way but a good indicator. Also due to different gene expression looks are also not a foolproof indicator. The only way to tell 100% is to have a DNA test after they are born.

twinmom1121

I've read a lot of times that identicals tend to have different head shapes more than fraternals. there's no sure way of knowing in the womb, but after they are born look at the features. Obviously if they are boy/girl they are fraternal. My boys were di/di and to me they looked so different but to everyone else they looked exactly the same. I was told fraternal my whole pregnancy from my doctors. We did the test at a year and they ended up being identical!

EmJ628

Our boys were di/di and they did not look similar at birth but the hospital did a blood type test which confirmed they are fraternal bc they have different blood types. So DNA not always 100% necessary

MrsCaseyK

All good stuff! I love twins!! Haha and it's so funny how often we get asked if our BG twins are identical.

Babies can look different and be identical due to epigenetics where they have the same genes but express them differently. More rare but possible. I know of another twin mom who thought her twins were fraternal but ended up being identical after the DNA test.

And fraternal can have the same placenta depending on when you find it. If they implanted close together and then grew together it could appear as one placenta. Also more rare, but a possibility. If it's early enough in pregnancy and they are one placenta it's almost for sure.

My doctor said my twins placentas were the only ones he'd seen that were COMPLETELY separate.

SoManyBoys

My twins had TTTS so I knew they shared a placenta and were identical.  I don't wish that on anyone, so I hope for you it is just a waiting game until they are born

nanamp

@chickaboo1974 - why weren't you allowed to see them in the NICU?

Julie21613

My g/g/ twins were delivered in July.  We did IVF and transferred 2 eggs.  We just assumed that both eggs took and they were fraternal as they did not share a placenta.  Now we aren't so sure.  They look really do look exactly alike.  The hospital nurses and pediatricians all said they were identical.  We may do dna testing to be completely sure.  Only way I can tell is one's face is a bit fuller then the other...my DH can only tell them apart when they are side by side.  If I'm holding one and the other is in her swing....he always has to ask!

blondekates1

My perinatologist told me at 18 weeks that my di/di boys were fraternal. I was shocked bc I thought you had to wait until birth to determine for di/di same gender. He said he could tell by the cross section of the placenta on the ultrasound. No idea what that means, but he is the doctor! Not shocked it's fraternal as I have twins on both my mom's and dad's side.

chickaboo1974

nanamp said:

@chickaboo1974 - why weren't you allowed to see them in the NICU?

I was not allowed in the NICU since I had severe pre-e (and then a serious drug reaction) and had to stay hooked up to mag for 24 hours.  I was taken to see them 24 hrs after they were born.

blairdavis99

chickaboo1974 said:

nanamp said:

@chickaboo1974 - why weren't you allowed to see them in the NICU?

I was not allowed in the NICU since I had severe pre-e (and then a serious drug reaction) and had to stay hooked up to mag for 24 hours.  I was taken to see them 24 hrs after they were born.

That happened to me too. The mag was terrible. I met my babies after my entire family had. So frustrating!

spoonleg

blondekates1 said:

My perinatologist told me at 18 weeks that my di/di boys were fraternal. I was shocked bc I thought you had to wait until birth to determine for di/di same gender. He said he could tell by the cross section of the placenta on the ultrasound. No idea what that means, but he is the doctor! Not shocked it's fraternal as I have twins on both my mom's and dad's side.

I'm not sure how your perinatologist could possibly know that by looking at the placentas. My di/di boys have been tested and are identical. If your boys look alike (same hair/eye color) and have the same blood type, they could likely be ID.

kaleyboo

I found out at 9 weeks. Mine were separate sacs but shared a placenta. My Dr told me it's every 1 in 350 and fraternal are every 1 in 99. If you are past 10 weeks it's possible if you have fraternal (separate sacs/separate placenta) that the placenta could have merged into one, making it seem identical but in reality it isn't. So the only good way to tell is blood tests after birth.

ijaclyn

I didn't get a chance to read all the responses but as an sonographer you can tell on ultrasound in the first trimester. If the separating membrane has a "Lambda sign" (thick triangle) and the membrane itself is thick they are most likely di-di twins AKA fraternal. If there are 2 placentas and 2 sacs, automatically fraternal. If you don't have an ultrasound until later in pregnancy, you can still visualize the membrane but it gets harder to call as babies get bigger. One way to tell then is if you have placentas in different positions, then you have a di-di pregnancy. However if you have a placenta that is either only anterior or only posterior it would be hard to tell if it is 1 or 2 fused together. Of course any time the gender is different it is automatically a di-di pregnancy. GL!

2.red.heads

Oh my gosh, all I can say is I can't believe I'm having twins! I have only known for 2 days and I feel like I've already read so much about this wild ride ahead of me! It's all so new and interesting!

twinmom1121

ijaclyn said:

I didn't get a chance to read all the responses but as an sonographer you can tell on ultrasound in the first trimester. If the separating membrane has a "Lambda sign" (thick triangle) and the membrane itself is thick they are most likely di-di twins AKA fraternal. If there are 2 placentas and 2 sacs, automatically fraternal. If you don't have an ultrasound until later in pregnancy, you can still visualize the membrane but it gets harder to call as babies get bigger. One way to tell then is if you have placentas in different positions, then you have a di-di pregnancy. However if you have a placenta that is either only anterior or only posterior it would be hard to tell if it is 1 or 2 fused together. Of course any time the gender is different it is automatically a di-di pregnancy. GL!

2 placentas and 2 sacs doesn't automatically mean fraternal though.. My di/di boys we tested and ended up being identical.

littlesocks

twinmom1121 said:

ijaclyn said:

I didn't get a chance to read all the responses but as an sonographer you can tell on ultrasound in the first trimester. If the separating membrane has a "Lambda sign" (thick triangle) and the membrane itself is thick they are most likely di-di twins AKA fraternal. If there are 2 placentas and 2 sacs, automatically fraternal. If you don't have an ultrasound until later in pregnancy, you can still visualize the membrane but it gets harder to call as babies get bigger. One way to tell then is if you have placentas in different positions, then you have a di-di pregnancy. However if you have a placenta that is either only anterior or only posterior it would be hard to tell if it is 1 or 2 fused together. Of course any time the gender is different it is automatically a di-di pregnancy. GL!

2 placentas and 2 sacs doesn't automatically mean fraternal though.. My di/di boys we tested and ended up being identical.

Identical twins can end up with separate sacs and separate placentas if the egg splits within the first 1-3 days of conception (fertilization?) - something like that. So yea, you're right

twinmom1121

Ya it depends on when the egg splits! I think a lot of ppl (and doctors) just assume di/di means fraternal! We were told our whole pregnancy that they were Fraternal. I think it's more common than people think too!

spoonleg

ijaclyn said:

I didn't get a chance to read all the responses but as an sonographer you can tell on ultrasound in the first trimester. If the separating membrane has a "Lambda sign" (thick triangle) and the membrane itself is thick they are most likely di-di twins AKA fraternal. If there are 2 placentas and 2 sacs, automatically fraternal. If you don't have an ultrasound until later in pregnancy, you can still visualize the membrane but it gets harder to call as babies get bigger. One way to tell then is if you have placentas in different positions, then you have a di-di pregnancy. However if you have a placenta that is either only anterior or only posterior it would be hard to tell if it is 1 or 2 fused together. Of course any time the gender is different it is automatically a di-di pregnancy. GL!

Wrong.

geekgirl613

I am currently pregnant (32 weeks) with identical twins and they told me on the very first ultrasound they were identical.  I will be having Mono/Di twins, so they have their own sacks (very thin membrane separating them), but one placenta.  From what I gather, it is easier to tell very early if they are identical because sometimes on fraternal twins the placentas kind of merge and can look like one placenta.  With that being said, there are special concerns with identical twins that aren't present for fraternal twins.  For example, I have had ultrasounds every 2 weeks to look for Twin To Twin Transfusion Syndrome which basically means one twin can steal nutrients (blood, fluid, etc) from the other.  You could also google Di/Di ultrasounds and compare it with your ultrasound pictures.  I was surprised at the difference when I looked it up (Di/Di vs Mono/Di).

Theliops

I concur with the ladies stating that di/di twins are LIKELY fraternal but you won't know for sure unless you have some sort of testing - or they have different features like hair colour or blood type.

We had an amnio at 20 weeks on both of our di/di twins and because of that we learned our girls are fraternal. It wasn't something we were concerned about knowing prior to birth but the hospital that did my amnio is very careful about making sure they get a sample from each sac (rather than two samples from the same one!) so they made it a point to make sure the two samples were distinguishable from each other - and to what degree. So it was a pleasant surprise to learn they're fraternal!

MoDiSafety

Do they have separate sacs & a shared placenta? Identical. Are they opposite genders? Fraternal. Do they have separate sacs & separate Placentae, yet are Same Gender? PROBABLY Fraternal, yet about 30% chance of Identicality from Early Cleavage :-) Won't know til they're Born if that's the case