How is Vanishing Twin Syndrome identified?
Before the use of ultrasound, the diagnosis of the death of a member of a multiple pregnancy was made through an examination of the placenta after delivery. Today, with the availability of early ultrasounds, the presence of twins or multiple fetuses can be detected during the first trimester. A follow-up ultrasound may reveal the “disappearance” of a twin. For example, a woman may have an ultrasound at 6 or 7 weeks gestation. The doctor identifies two fetuses and the woman is told she is having twins. When the woman returns for her next visit, only one heartbeat can be heard with Doppler. A second ultrasound is conducted and only one fetus is observed. Sometimes a woman may have symptoms that would indicate a miscarriage, yet, with an ultrasound, a single baby is found in her uterus. Vanishing twin syndrome has been diagnosed more frequently since the use of ultrasonography in early pregnancy. A conservative estimate of frequency is that vanishing twin syndrome occurs in 21-30% of mult
