[wizardoz]

It's pretty bizarre. I guess these embryos would have had to fuse before being implanted, eh? We're talking about embryos only days old... right?

[MHGinTN]

You got it! I don't think twinning occurs past day fourteen from conception. The 'hatching' from the zona pellucida occurs around day four to six, so I would guess the two embryos had to be in proximity when they 'hatched' AND somehow the encapsulation of both got welded togewther to form one placenta while the embryo bodies welded together within a blastocele. Bee zar