Tue 8 May 2012
Identical or Fraternal? One in Seven Twin Parents may be misinformed
Posted by KathrynWhiteley under Expecting Twins, Giveaways, Twin Tips - Infants
[217] Comments
While most Parents of Twins report to TwinParenthood that it is important to them to know if their twins are identical or fraternal, the reality is that many are misinformed during prenatal scans, according to UCL researchers in a commentary piece in BJOG[1] (a journal of Obstetrics and Gynecology).
Out of the 1302 families with same sex twins in the cited study who stated they had been given the information by health professionals based on the formation of the placenta as seen on the prenatal scan, 191 (14.7%) were misinformed about their zygosity.
It seems that correctly identifying if twins are identical or fraternal is trickier than some health professionals may realize.
It may be that some health care professionals actually perpetuate the common mistaken belief that all twins sharing a placenta are identical, and that twins with two placentas must be non-identical. But in fact, 25-30% of identical twins can have two placentas, according to the researchers. Separate placentas can develop in monozygotic twins when the egg splits within 2 days of fertilization.
Parents may have originally been told that their twins are non-identical (or fraternal) because of the formation of two placentas. But, if your same sex twins share eye and hair color, and are often mixed up by those around them, your twins may actually be identical. Twin Zygosity Testing (or Twin DNA Testing) might be your best option to determine if your twins are identical or fraternal.
Zygosity is the genetic relationship between two twins. With respect to genetic similarities or dissimilarities, twins are classified as identical or fraternal.
Monozygotic = 1 egg – identical twins (when one egg is fertilized by a single sperm cell and then splits).
Dizygotic = 2 eggs – fraternal or non-identical (when two eggs are independently fertilized by two sperm cells).
[1] van Jaarsveld C, Llewellyn C, Fildes A, Fisher A, Wardle J. Are my twins identical: parents may be misinformed by prenatal scan observations. BJOG 2012;119:517–518
Zygosity Test Giveaway
Our friends at Proactive Genetics have graciously offered a Zygosity test to one randomly selected TwinParenthood reader.
05/21/2012 UPDATE: Giveaway entry is now Closed. Thanks to all who entered! Our winner is Reagan K of Arcata, CA — Congratulations, Reagan!
Proactive Genetics offers a great service to parents of twins – for a fantastic price. The genetic testing is easy – gentle swabbing to remove cheek (buccal) cells – which contain adequate DNA to perform the zygosity test. And then mail it in. Easy-Peasy. Have questions about twin zygosity or zygosity testing? Check out thier informative Frequently Asked Questions About Twin Zygosity page.
Basic (required) entry: Please visit Proactive Genetics and find the first word on their website that begins with the same letter as your first name. Then, come back and post a comment here with the word, your first name, and tell us if you were told that your twins are identical or non-identical. Do you suspect that you might have been mis-informed?
Additional Entries:
Post a comment here for EACH entry.
- Basic Entry (above) is required before any extra entries will be counted.
- Tweet: Identical or Fraternal? 1 in 7 misinformed: http://bit.ly/JXPrWL @TwinParenthood DNA Test #Giveaway (ends 5/16) #tph #multiples #twintuesday
- Publicy share our Facebook giveaway announcement to your own timeline (share must be visible to “public”).
- Post a comment on one of our Facebook giveaway announcements.
- 5/14/2012 Update! We’re adding a new way to earn an extra entry: Post a photo of your twins on our Facebook wall and tell us (with the photo) if you were told they are identical or fraternal. (Please be sure to come back and post a comment here to earn your extra entry!)
As usual, the standard TwinParenthood giveaway rules apply — read them all here. Giveaway is open to US and Canada. Contest Entry closes 11:59:59 pm on May 16, 2012.
05/21/2012 UPDATE: Giveaway entry is now Closed. Thanks to all who entered! Our winner is Reagan K of Arcata, CA — Congratulations, Reagan!
Laboratory! We were told they were di-di twins and later found out two girls. I don’t think we’ve ever been told identical or fraternal officially, but our current theory is mirror image identicals. I think the idea of semi-identicals came up about the time my girls were born as well (one egg, two sperm). We’ve always wondered, but have been too cheap to have the test officially done. Almost six years old now!!
(Montgomery) was first word however was in a comment a customer left otherwise there were no M’s. Told my twins are fraternal. 2 of everything. However after reading an article I am in question because everyone swears my kids are identical because they apparently lookkeith it toand everyone (not to me, maybe because im momma) and its always annoyed me because my doctors in germany (military) told us that they were absolutely not identical having own placentas and all. So now it bugs me that maybe ive been mislead all along. Now I am concerned!?!?!
I was told my girls were identical but while they look similar I find there are major differences in them. I would love to know.
Don’t forget to visit the Proactive Genetics website and find the first word on their website that begins with the same letter as your first name. Then, come back and post a comment here with the word, your first name, and tell us if you were told that your twins are identical or non-identical. Do you suspect that you might have been mis-informed? Good Luck! ♥ Kat
First word is login and i believe my girls are non identical they have very similar looks and look alot alike i however dont think they are..the dr wasnt sure as there were two sacs but one they came out they were in 1. I would love to know for sure
(Results – Nichole) My twins are fraternal (one boy, one girl). They look nothing alike, although when they were babies, everyone in the general public deemed it necessary to ask if they were identical. 7 years later, they look even more different than they did when they were born. My son also weighs about 10 pounds more than my daughter and is about 3 inches taller than her.
They cannot be identical if they are a boy and girl. Um…the parts are not identical. Impossible.
Not enirely impossible, actually. It’s possible, just very very rare and involves a chrosonal abnormality in the girl twin.
There have been less than a dozen cases of this abnormality, which involves Fragile X disorder in the Identical Twin environment. The resultant Turner’s Syndrome in the “Female” twin is Lethal, the “Male” twin is damaged by Fragile X. I wish people would be more Precise in describing this issue rather than showing it as some kind of “Cool Medical Curiosity.”
At-Home,my first name is Allison. I have twin boys. We were not given a definite answer if they are identical or fraternal. It appears they had one placenta and two seperate water sacs. They look like they could be identical but all my other children look so much a like, it is hard to tell. They also both have cerebral palsy. It would be nice to know!
Sounds like your twins are probably identical. 2/3 of identicals have one placenta and separate water sacs, so that’s the most common occurrance of identical twins. Only about 1% of identical twins split so late that they share the same water (amniotic) sac.
Testing-Tricia
I was told my twins are identical although I feel like they look nothing alike! They have so many differences and 1 has a birth mark that the other does not have. My girls are now 16months old and I would love to know! Thanks!
Hi Tricia! One of our identical girls has a birth mark that the other does not have — birth marks are not identical
We had been told that our girls were fraternal — separate placentas, but suspected for years that they were identical — a DNA test last year confirmed… yes! they are identical. ♥ Kat
It would be great to know for sure! I, like most, don’t have the $$ to put towards this. It would be good to know for any medical problems that could arise in their future.
AFFORDABLE.
I have two sets of twins. I was told my first set (B/B) were fraternal – they don’t look anything alike – they had 2 separate sacs with a very thick separation. My second set (G/G) we have been told both by many medical people. Some think they are identical and some think they are fraternal. My girls each were in their own sac but the membrane was paper thin and we think they shared a placenta.
The first word would be “DNA”, but that’s not actually a word so “days”. I have Identicle boys. Most people who see them think they look identicle however our family has always wondered as there are so many difference between them.
Our twins are di/di identical. Their placenta was actually two fused. So we ended up getting their dna tested. So glad we did, but it’s really obvious they are identical to us as well as everyone else around us.
Rate! My little girls look identical- have all recessive phenotypes: blonde hair blue eyes and I’m a typical Mediterranean woman. My OBGYN could never say with confidence whether or not they
Were identical in the womb. I would love to know!
Home. We were told pretty much from the start they were probably identical. To this day (they are 2 this month) they look nearly the same but as parents we wonder just cause we can generally tell them apart to well. We would love to know for sure.
Heather
Tweeted: Identical or Fraternal? 1 in 7 misinformed: http://bit.ly/JXPrWL TwinParenthood #Twin DNA Test Giveaway (ends 5/16) #twinTuesday #multiples
just!!! we were told they were not id. that there was no way they swore there were two sacs and two plecantas but then said it was one plecanta and then said it was one but two fused. when they came out the main MD said oh no they dont look nothing alike……. to this day i have to look at both children to see who is who. i cant not just guess on my own and i am their mother!
“About”. I was told my twins are identical, most likely. I do not know for sure and would love to find out! They are girls with same eye and hair color and shared the same umbilical cord.
Shared from your facebook page!
I shared, Commented and tweeted!! =)
Login. My girls look alike sometimes and sometimes, to me anyway, they look very different. They shared a placenta but were in two different sacs. They did tests on the placenta but the results came back undetermined so we still don’t know for sure if they are identical or fraternal.
Commented on facebook post!
Dichorionic- its been a mystery since my boys (Ian & Alek) were born. My OB swore she thought they were identical, but they were in separate bags. They tested the placenta? But she said they werent able to tell. Everyone mixes up the boys! Even my husband and I on an off day :/ I honestly have left to the store with Alek thinking he was Ian! I discovered I had the wrong twin at the store! They both drink different formulas, and I had taken the wrong one! Obviously. This has happened a few times to me. It would be wonderful to find out if they were identical or fraternal.
KNOW was the first word. My name is Kristin I have 6 month old twin boys my ob Dr told us he couldn’t tell for sure but thought they were identical if he had to guess however I went into premature labor and was shipped to a different hospital with a NICU and was told by another Dr that did an ultrasound that they were fraternal. After I had the boys they said the placenta was inconclusive so the only way to know for sure would be through a DNA test. My boys look so much alike that I really think they are identical and would love to know for sure!
Hello i was never told what mine were. I have twin girls they will be 3 in October. Mine look a lot alike and people often ask me if they are identical. I never know what to say half the time they are and the other half I say they are not. I’m just not sure and sometime I feel stupid because I can’t tell someone if they are or not. At this point in my life we just can’t afford the test so someday I hope for the girls mostly they will find out!
I forgot my word it was since lol!
Nice-Natalie. We were told our twin girls are fraternal because they were in seperate sacs. They look identical and everyone always ask if they are identical. We would like to know for sure whether they are fraternal or identical.
First word is “Easy”. I was told that my boy-boy twins were fraternal because they had seperate placentas and were in seperate sacs. Every time I questioned my OB about it, he said “they inspected the placentas and they know”. The twins have the same hair/eye color, have always been the same weight and height, and nobody can tell them apart!
I comment of the facebook page and shared it with all my other twin mommies on my facebook !
SEARCH was the first word. We were told that our girls were “di/di, so they’re not identical”. They have the same eye color, but slightly different shades of hair color. Their facial expressions, however, look very much alike. In the NICU and even now, people ask if we’re “sure” they’re not identical, so it would be interesting to find out!
Mission—– I was told my twin girls are identical because they had 1 placenta and twin to twin transfusion but I really feel they are fraternal , they look different and I know size wise was expected but I would love to have an answer.
“We” – Wendy. I was told they are fraternal but they look an awful lot a like. I mistake them a lot which is bad because the mother is always supposed to know which kid they are holding. I would love to find out for sure.
At-home, My first name is Amelia. We were told our twins girls were fraternal, but we’ve always wondered if they were actually identical. People often can’t tell them apart because they look so similar. They have always had a large weight difference, so it’s never been hard for us as their parents to tell who is who, but there are times were even we see what everyone else says about how they are hard to tell apart! I’d love to know for sure!
Testing – Tara
We were told our twins were identical but you couldn’t tell by looking at them. Weight difference, height difference has always been present. I’d love to know for sure!
First word- having
My name- Holly
My boys were in separate sacs at my first ultrasound @ 9 weeks, so we just assumed that they were fraternal. After I had them, we started to wonder if they might actually be identical. At my 6 week post-partum check-up, my doctor informed me that tests had been performed on the placenta, and the results were identical! I totally believe that they’re identical; I even mix them up sometimes and they’re 15 months old now!
Shared the giveaway on my facebook timeline!
I shared this on my wall!
I commented on your Facebook post!
I tweeted!
Easy – We were initially told our boys were identical, then a ultrasound tech convinced us that they were fraternal and suggested we find out the sex. We have 2 boys so that solved nothing. We still don’t know! Everyone but my husband and I think they look exactly alike!
C- section- Christina. We were told our boys are fraternal. We can tell them apart but most others cannot. People are always telling us “No, you are wrong they are identical”. I am ready to know myself because I think all these strangers may be right
(Lab. My name is Laurie) I was told before I gave birth to my twin boys that there was a possiblity that they could be identical but most likely fraternal since that were di/di. Seperate sac, seperate placenta. Once they were born, we kind of suspected they were fraternal. Different look, differnt hair, differnt ears. NOW WE KNOW FOR SURE. Different hair and eye color!! LOL.
“Kathy” in testimonials – Kristy. We were told that our boys are fraternal. Most people can not tell our boys apart. We ofcourse can as their parents, but sometimes when looking back a pictures I have to really look twice. Thank you for offering this service!
{Did} We were told our boys were identical. They were in separate sacs and shared a placenta. They look different to me most days, but most people can’t tell them apart
Easy, My name is Elizabeth. At 11wk scan my twins werr in the same sac. The dr. said they were identical. When they were babies they looked different; one was a,little more bald and bigger which was my baby b. Now, they are almost 2 and at times they look identical whete even I have to do a double take but most of the time they look different. I am the mom of coutse so it must be the instinct of the little quirks of each twin, but I definitely would love to know officially!
Results!
Live in Ohio, 2 year old Boys! We were never told anything other then they shared same placenta but we think identical!Doctors told us if we wanted to some test done it would be costly. <3 to know though.
Testing-Tina. I asked my doctor if they were fraternal because we had 2 placentas and everything. He told me he couldn’t tell for sure just with an U/S. So I did a lot of research and found out the facts. Mine look so much alike, but I can tell the differences. When people ask me what they are, i just agree…’sure, they are identical’..lol But I really don’t know! However, I have a friend pregnant with twins right now and they have separate everything and the U/S tech told her that they are definitely fraternal, like, not possible to be identical. I will email her this article.
Good! It’s amazing how so many u/s tech don’t know that you can’t rule out identical by ultrasound.
Except of course boy& girl
The word is “still”..my name is Sophie. We were told that our boys are DCDA as we’re in separate sacs and apparently had separate placentas..but to look at them you would (and everyone does) think ID. Even I sometimes struggle and they are 9mths! Stanley has a small ski tag on his ear lobe so not sure if this would rule out them being ID? I would LOVE to find out for sure…
About was the first word.. i was told mine are identical and they look it id love to know for sure
Zygosity was the first word and my names Zara, I have twin girls aged 2.5yrs we were told there are non I’d as two eggs but we are not convinced they look solo alike. I’d be really interested in finding out.
Just – I was told by ultrasound 95% chance they are identical. Our boys look identical, but I can easily tell them apart. Would be great to know with Proactive Genetics test.
Shared and commented on fb!!