Has there ever been double twins born?

You can have twins from two eggs being fertilised or two sperms simultaneously fertilising an egg. Have these two things ever both happened so that there are identical twins and also an unidentical twin?


OK, it's been explained to me that the egg splits in two then gets fertilised or there are two different eggs. Premise of the question still exists - has there ever been identical twins born with unidentical?

3 Answers

  • 8 years ago
    Favourite answer

    Twins happen in one of three ways. One way is that two eggs are released and they are each fertilized. The next way is that one egg is released and fertilized by two sperm. (Very rare 1% of twins and they usually don't survive). These are fraternal twins. (Although the second kind are called semi-identical because they have the same egg.)

    The other way is when a fertilized egg splits in two. This make identical twins. If the egg doesn't split completely, then you have conjoined twins.

    What you are talking about would be triplets. One fertilized egg would split for identical twins and another egg would be fertilized. And yes, it has happened. But often, there is no way to tell if they all look alike unless they have DNA testing.

    For higher order multiples, it is more common. The Fischer quints, born in the 60s, had 3 identicals (one egg split three ways) and 2 fraternals. ]

    I think what you are saying is that a set of twins gets created by two sperm hitting one egg, then splitting into two as semi-identical twins, then one of those splitting into two as identical twins, resulting in triplets - two identical and the third semi-identical to the two. I couldn't find any examples of that, but it would take DNA analysis to prove it and most folks dont' get that. So while it is possible (and very rare), there aren't any documented cases of it that I could find. Of course, they could have happened and the testing just hasn't been done.

    Pink, go back to nursing school. You failed this one. Which makes me wonder if you are lying about being a labor and delivery nurse.

    Source(s): Twin http://www.americanpregnancy.org/multiples/howmult... (Read the last paragraph) The case of one egg and two sperm: http://news.bbc.co.uk/2/hi/health/6498215.stm
  • 8 years ago

    You don't get twins from two sperms simultaneously fertilizing one egg. That's not how it works. Either one egg splits into two and you get identical twins or two separate eggs gets fertilized by two different sperm at the same time.

    Sperm don't divide - eggs do

  • 8 years ago

    I don't think it's happened before if so it's really rare

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