Vanishing Twin Syndrome
Definition - What does Vanishing Twin Syndrome mean?
Vanishing twin syndrome occurs when one of two twin fetuses miscarries during pregnancy, but the other survives. Vanishing twin syndrome may occur during a pregnancy with any number of multiple fetuses. While vanishing twin syndrome may impact twins conceived naturally, it is more likely to occur during an in vitro fertilization (IVF) procedure, when multiple embryos have been transferred.
FertilitySmarts explains Vanishing Twin Syndrome
Vanishing twin syndrome is diagnosed when an early ultrasound identifies two or more fetuses, while a later scan only recognizes one pregnancy (or a reduced number, in the case of multiple gestation). Some women may experience symptoms of miscarriage, including cramping or vaginal bleeding.
The exact cause of vanishing twin syndrome is unknown, and there is undoubtably multiple causes. Typically, chromosomal abnormalities in the genetic disposition of the vanished fetus is evident.
If the fetus vanishes during the first trimester, the remaining fetus and mother are typically unaffected. However, if the fetal loss occurs during the second of third trimester there is an increased risk to the remaining fetus and mother.