when did you find out if the twins were identical or fraternal?

We found out at our first OB appointment, at about 8 weeks. The doctor pointed out that there was a membrane seperating the two sacs, and apparently that means they are fraternal.

 

quote:
Originally posted by MomToBeX2:
We found out at our first OB appointment, at about 8 weeks. The doctor pointed out that there was a membrane seperating the two sacs, and apparently that means they are fraternal.


for some reason doctor's don't understand the concept that if the egg splits early, then there will be 2 sacs meaning that they could still be identical.

The thickness of the membrane doesn't mean anything regarding whether they are fraternal or identical.

 

quote:
We found out at our first OB appointment, at about 8 weeks. The doctor pointed out that there was a membrane seperating the two sacs, and apparently that means they are fraternal


Okay, this is driving me nuts!!! Are Doctors reading the research? My boys are as identical as you can get, nobody can tell them apart. They had two separate sacs, they did not share anything... Why is this so hard to understand?

Heather, I am not frustrated with you, not at all. My doctor told me the same thing... I just don't understand how we can know that the membrane has nothing to do with zygosity, but some Dr.'s don't... I started a thread saying, "Don't assume they are fraternal" so other twin Mommies would know that even 30% of ID twins have separate sacs.. Why are these Doctors not aware of this?

 

We got our first u/s done at 11 weeks, same time we found out they were twins, and the u/s tech told us they were definately frats b/c of there being two sacs and a very thick membrane, so we went around telling everyone we knew they were frats...then after reading some posts on here I learned my u/s tech didn't have a clue what she was talking about. I asked my doc and she confirmed what some of the posts had said, that there was no true way to know until we confirmed the sexes or if they were same sex, and they were, we would have to rely on other means...well those other means failed. LOL, mine have the same blood type, so the only way for us to find out is to do the testing, and we haven't, YET. My girls were in separate sacs and had separate placentas, so the odds favor them being frats, but they could be ID's!!! We get TOTALLY mixed comments on them...some people ask us how we can tell them apart and others ask us if we are sure they are twins!?!?! I think they favor more now than they used to, but of course, to me they don't look 100% alike.

 

I suppose when you have same sex twins, you will never know if they are identical until you have the test done. But my doctor said the the same thing as Heathers. The large membrane wall, 2 different sacks, fraternal. And mine were fraternal as fraternal get. Doc also said that identicals share a sack and a placenta. When they are sharing the sack, the membrane is paper thin.

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I think that if you did not have an early scan it is immpossible to tell unless you have a DNA test. For example the famous Mary-Kate and Ashley Olsen Twins are fraternal and not identical.

 

If you don't have same sex twins....there is a 99% chance that they are fraternal (there is that rare chance that you can have opposite sex that are id...but that's another post).

If you have same sex twins, you won't be able to tell if they are ID or FRAT (almost typed fart ) by how thick or thin the membrane is. You will be able to tell by how they look..ie different hair colors, or by them having different blood types (things you should find out during your hospital stay). If they look very similar, (as in my case) you would have to get them tested to find out for sure.


As far as the olsen twins, I believe that their mom was told the same thing as every other mom of twins that has a doctor that doesn't know. That they are fraternal if they didn't share a placenta. I don't believe they were ever tested.

 

I think it's quite crazy that doctors are STILL telling women that 2 placentas = fraternal when it is widely known through the wonders of DNA testing that this is not the case.

Are any of you who are being misinformed correcting your doctors? I didn't have to -- mine told me correctly that the majority of di/di twins are fraternal but that since they were both boys, we wouldn't know until after birth. The ultrasound tech said the same thing. I guess I got lucky enough to find medical professionals who believe in continuing their education.

 

Our boys were di-di, but we knew for sure they were frat when we found out their blood types after they were born - one is O+ and the other is B+, so they certainly can't be identical!!

 

I'm also frustrated by the number of medical professionals who don't know the basics of twinning. Here is an article on the internet.

http://www.emedicine.com/ped/topic2599.htm

quote:
Monozygotic twins develop when a single fertilized ovum splits during the first 2 weeks after conception. Monozygotic twins also are called identical twins. An early splitting (ie, within the first 2 days after fertilization) of monozygotic twins produces separate chorions and amnions (see Image 1). These dichorionic twins have different placentas that can be separate or fused. Approximately 30% of monozygotic twins have dichorionic/diamniotic placentas.

Later splitting (ie, during days 3-8 after fertilization) results in monochorionic/diamniotic placentation (see Image 2). Approximately 70% of monozygotic twins are monochorionic/diamniotic. If splitting occurs even later (ie, during days 9-12 after fertilization), monochorionic/monoamniotic placentation occurs (see Image 3). Monochorionic/monoamniotic twins are rare; only 1% of monozygotic twins have this form of placentation. Monochorionic/monoamniotic twins have a common placenta with vascular communications between the 2 circulations. These twins can develop twin-to-twin transfusion syndrome (TTTS). If twinning occurs beyond 12 days after fertilization, then the monozygotic pair only partially split, resulting in conjoined twins.


Edit: I just found this article, that is easier to read
http://www.obfocus.com/high-risk/twins/twin1.1.htm

 

quote:
Originally posted by Jennifer P:
As far as the olsen twins, I believe that their mom was told the same thing as every other mom of twins that has a doctor that doesn't know. That they are fraternal if they didn't share a placenta. I don't believe they were ever tested.


I agree. I've never heard anything about them getting tested. They were probably di/di and then had different personalities so everyone who knew them could tell them apart. So many people believe that if twins are not exactly alike then they're either fraternal or there's something wrong.

 

I was told the whole pregnancy that my twins were identical but I didn't know for sure until they were born. They test the placenta.

 

We didn't officially find out they were ID until after they were born and the placenta was send out for pathology.
They really didn't look that much alike at birth, aside from the same dark hair and dark blue eyes, they had different hair-parts, and a pound difference.
So basically you are gonna have to wait to find out 100% until after they are born, the wait does kinda suck when people ask constantly if they are frat or id! p

 

I was told my entire pregnancy that mine were definitely ID. We found them via u/s at 14 wks and they "definitely shared" a placenta. There was only a hair line thin membrane between them and their growth and heartrates were almost the same every appt until about 30 wks. They then developed an alleged weight discordnace of 2 pds so then they were even more certain they were ID's and very concenred about TTTS. We watched closely and waited it out and I ended up going all 40 wks with them. And when I delivered they were not really looking ID at all! LOL! Sure enough, the u/s was way off since they were so big and it couldn't get accurate measurements. They only were a little less than 1 pd apart at birth and after the pathology report came back on the placenta we read "2 placentas fused. Very hard to distiguish fusion sight but 2 placentas and fused sight found"...or something along those lines. We didn't find this out til months later when we requested a copy of the report! So, for 3 months I wondered, all the while looking at them thinking there's no way they're ID! LOL! One has red and one has blond hair! Otherwise they do look alot alike! LOL!

Nikki - wife of a firefighter/paramedic and mom of 7
ages 8, 6, 3, 2 yr twins, 8 mo and baby #7 due 7/07