When you have identical twins, the you have one egg and one sperm. It splits. When you have Siamese twins, the egg doesn’t split all the way. (If I have any of this wrong so far, please correct me. As if I need to say that.)
I think that most cases of Siamese twins wind up as miscarriages, but quite a few in history have made it. Enough, I’d think that at least ONE set of Siamese triplets would have been recorded somewhere. I guess this opens up a bunch of questions for me:
Why aren’t there any Siamese triplets? Or are there and I just haven’t heard of them, or couldn’t find them? Is it possible that there have been several cases of this happening, but none lived to be born? Or is this not genetically possible?
There are no documented cases of true conjoined triplets, but there have been cases of triplets with two of them being conjoined and the third separate. Do a google search for “conjoined triplet” to learn more.
I believe that most (if not all) triplets are one set of identical twins and a fraternal sibling.
That is, triplets occur when: [ol][li]A woman releases two ova during ovulation.[]Both are fertilized (by seperate sperm, obviously).[]The parents say Hi! to Opal.One ovum splits, developing into identical twins.[/ol][/li]As you said, conjoined twins would develop if the split was incomplete. The third triplet, being from an entirely different egg and sperm, would develop normally. Becauseof this, it’s possible for a woman to concieve triplets, two of whom are conjoined and by one father, and then have the third concieved by another man! Now that’s a springing episode I’d like to see!
I previewed, I swear.
That’s a Springer episode I’d like to see.
Next time, why Lurkers have no typing skills. Until then, take care of yourselves, and each other.
Triplets come as fraternal triplets (all from different eggs), one pair identical + one more egg, and yes, there ARE identical triplets.
Given that triplets are much rarer than twins, identical triplets (required for triple-conjoined) are the rarest of triplets, and the mortality rates for conjoined anything… while theorectically possible, I wouldn’t be surprised if there’s no history of it actually happening.