A Rare Occurrence
The answer was quite simple. Donna was a half-Jamaican woman, whereas Vince was Caucasian. Therefore, their twins were of two different races. The chances of this happening were rare, but not impossible. According to Dr. Jim Wilson from the University of Edinburgh, there’s a one in 500 chance for a couple to have biracial twins.
Obviously, the Aylmers were shocked upon seeing their newborns at birth because they didn’t have the slightest clue. Skin colors don’t show on the ultrasound, so it was unlikely for anyone involved to have known about their differences.