Twins with Different Fathers

The Discovery Channel has told the story of a more recent pair of mixed-race twins in Europe. A couple went to a clinic to undergo in vitro fertilization. The husband's sperm had fertilized one of the eggs.  A mix-up in the lab caused Mom's other egg to be fertilized with sperm from a different man, who happened to be black.

Newsweek reported a similar situation when, in addition to Mom having her own eggs (fertilized by her husband) implanted, she also had fertilized eggs from another couple mistakenly been implanted as well. As it happens, one set of parents were white, the other black.

Just because one twin is white and one is black does not mean that they have different fathers, however.  ABC and Discovery Channel have both done stories recently on twins of mixed-race couples; one twin with the features and skin coloring of mom, and the other with hair and skin coloring like dad.  In another family, both mom and dad were of mixed-race, and their daughters looked like they were from two different races.

If there is any questions about bi-paternity, DNA is usually the only way to prove if one man is the father of both twins or not.

Which brings up the question: when is a twin a twin? Do different fathers make twins half-siblings? An unofficial poll taken amongst mothers of multiples came to the conclusion: if they shared the womb at the same time, they are, in fact, twins. Regardless of genetic background, a bond develops during prenatal development that none of us singletons ever really understands, and that's what makes a twin a twin . . .