Vanishing Twin Syndrome:

What is Vanishing Twin Syndrome?

Vanishing Twin Syndrome occurs when one of a set of twin fetuses apparently disappears from the womb during pregnancy, usually resulting in a normal singleton pregnancy.

What really happens?

One of the fetuses in a twin pregnancy spontaneously aborts, usually during the first trimester; the fetal tissue is absorbed by the other twin, the placenta, or the mother, thus giving the appearance that the twin "vanished."

How often does it happen?

Scientists have confirmed that the number of twin conceptions greatly outnumbers the number of actual twin births. Some estimates offer that 1 in 8 people started life as a twin, while in reality only 1 in 70 actually are a twin. In "Having Twins," author Elizabeth Noble claims that 80% of twin pregnancies result in the loss of one or both babies. Other studies predict that Vanishing Twin Syndrome occurs in 21 - 30% of all multiple pregnancies in the United States. It is estimated that Vanishing Twin Syndrome will play a role in 50% of assisted ovulation pregnancies.