It is estimated that out of every hundred pregnancies, six go through the vanishing twin syndrome creating a twinless twin. A twinless twin is someone who loses a sibling who was a living or potential twin. The term can even be used for other multiple birth children.
There are three ways for someone to become a twinless twin. The first is the death of a living twin. The second occurs in utero when one of the twins dies due to a complication during the pregnancy or at birth. The third way occurs due to the vanishing twin syndrome, in utero.
When a twin is lost in utero, and the twins never meet in life, but the co-development in the womb for those few months will affect the twinless twin. Twinless twins speak of inexplicable confusion, loss or incompleteness. Losing a twin in adulthood after creating a stronger bond is quite tormenting. Aware twinless twins are often depressed or fear mirrors. Others are driven to live for both themselves and the dead twin, forcing themselves to work extra hard. Parents may only be aware of the first two losses of a twin, but a twinless twin will be aware of all three with or without being told. This suggests that very strong connections are forged in the womb between co-multiples.
A vanishing twin is absorbed by either the mother’s body or the other twin. Later in life some twinless twins can develop growths or pains in certain body parts and after medical examination, a whole or part of a vanished twin may be found and removed.