actually, the fear was a bit more complicated than that. they have something called 'twin to twin transfusion syndrome'
it's a complication that's typically fatal in about 80-100% of the cases that it shows up in.
although the twins don't share a sack, they do share a placenta, and there's a blood vessle that goes from one twin to the other.
(one twin gets too much blood, the other, not enough)
so far they are doing good (better than expected) we are currently at 25 weeks. if they make it all the way to 30 weeks, their chances of survival go from 20% up to about 80%. so that's good.
-RuskiFace the Pirate
(and thank you for the reminder Zone, I did get my wife a mother's day card)