Can you tell if twins are identical

[Fifi2406]

Before they are born or do you have to see when they arrive??

Yes they can. Apparently identical twins share a placenta.

As the other poster said.

My dh is an identical twin and my brother and sister (and aunt and uncle) are non identical twins. Also, usually if twins run in the family then they tend to be non identical whereas if they are random twins and not hereditary, they are more likely to be identical (or at least that's what I've always believed)

Actually, no, not with complete certainty.

Identical twins don't always share a placenta, it depends on when the egg/embryo splits. I think it's about 10% of twins that have seperate placentas and seperate sacs that turn out to be identical, DNA testing has proven them to be identical twins.

What midori said my twins had separate placentas and sacs and are identical

Echo the others - I have 2 sets of twins, both were 2 sacs and 2 placentas yet the girls are identical and the boys are non identical :-) no twins in the family either - they have to start somewhere I suppose!! Only definate way to find out is zygosity testing when they arrive :-)

Wow 2 sets of twins!!!!

If they share a placenta I believe they can only be identical, not fraternal. If they don't share a placenta they may still be identical depending on when the embryo split, and the only way to know for sure is to DNA test after the birth.

Ooh I wonder if anyone can help me with something my sister and I have puzzled over for years.

Sister has identical twin boys ( I have fraternal girls) - the boys shared a placenta and apart from a few extra freckles on one twin pretty much look physically identical but one was born with a small cleft palate. My sister and I had always assumed cleft palate to have a genetic cause - so why only one twin affected? Are the boys not really identical or was the cleft palate caused by environmental factors that affected only one twin?

Any ideas? (sorry to divert thread)