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Identical v Fraternal

Veronica
Ok, is it always that if they share a placenta the twins will be identical? And how do they determine when they'll deliver the twins via c-section? I know I've asked questions like these multiple times but my brain is like mush right now haha. I'm having mono/Di twins and was told they will be identical. Don't know if that's always the case? I've tried to google it but I don't get much information 
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COMMENT (17)

Ke

Posted at
Sorry Meagan, but Veronica is correct. If there is one sac and one placenta that is mono-mono. If there are two sacs and one placenta then that is mono-di. In both cases they are identical. It's impossible for there to be one sac and two placentas. The sac is inside the placenta. With identical twins, it all comes down to how early the egg split whether they share a sac or placenta.Now here is the interesting part: If there are two sacs and two placentas, there is still a chance that they are identical. Up until very recently many doctors said they were automatically fraternal if there were separate placentas and sacs, but it turns out upwards of one-third of identical twins have separate sacs and placentas. So many twins were identical who were told by doctors they were fraternal. So if there are separate sacs and placentas and they are the same sex, the only way to know for sure is to have a DNA test after they are born by swabbing inside their mouths. If they are different sexes then they are automatically fraternal.So yes, you're having identical twins. Congratulations!http://mobile.nytimes.com/2012/03/06/health/research/study-finds-twins-can-easily-be-misclassified.html?referrer=&_r=0

Ke

Keri • Aug 15, 2015
That membrane is what constitutes separate amniotic sacs.

Am

Amber • Aug 15, 2015
Actually they share an gestational sac, that's what makes this type identical. Mono/mono and mono/di both share a gestational sac. Mono/di have a membrane separating the sac so that have separate amniotic fluid.

Ke

Keri • Aug 14, 2015
Probably. Or there was a misunderstanding. A simple search on mono-di twins will clear it up.

Br

Posted at
If they share a placenta they will always be identical. :)

Ja

Posted at
If they share a placenta they are identical and 99% same sex so you'll end up with 2gurls or 2boys if they have a separate placenta they are frat twins but could still be identical due to when the egg split 

Me

Posted at
These are both ultrasounds of identical babies. This is what I mean about sharing the "main sac" they are both together. If they aren't identical they will be in two separate black areas. 

je

Posted at
anyways so after that girl said that to me i quickly looked for info and found this.

Me

Posted at
I think they are always identical if they share a sac. So mono-mono and mono-di babies are identical. If they have two separate sacs (if you realeased two eggs) they will be fraternal. They would determine the delivery date for how big the babies are and how long they think you will last. The goal will be to get you to at least 30 weeks. 

Ve

Veronica • Aug 14, 2015
Ok, I'm super confused because my twins share a placenta but have their own amniotic sac but share the same chorion. My doctor said she doesn't think I'll make it to even 34 weeks. Which im a little worried about. But she also said my twins would be identical since they shared a placenta?

Me

Meaghan • Aug 14, 2015
If they share a sac 1 egg was fertilized then later split to make two babies which would be why they are identical.
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