Vanishing twin

A twin detected in early pregnancy that is miscarried, frequently by resorption, without clinical signs or symptoms.

The surviving twin continues to grow and develop.

Of all twin pregnancies, 40% involve a vanishing twin and result in the birth of a single child.

There is a gene that influences the prenatal survival of dizygotic (non-identical) twins.

The gene is on chromosome 3 and is known as PPAR-gamma.

Twins carrying the same variant of this gene may develop at the same pace.

However, when the twins are carrying different variants of the gene, one twin may develop at the expense of the other.