Vanishing Twin Syndrome

Vanishing Twin Syndrome

Vanishing Twin Syndrome (VTS) and some common questions and answers about this phenomenon.



The answers below may not be suited to your situation. Please discuss any concerns you may have with your healthcare provider.

What is vanishing twin syndrome?

VTS is when one fetus of a set of twins seemingly disappears during a twin pregnancy. Usually the vanishing twin will either be reabsorbed into the placenta, mother, or the other twin. Otherwise the mother will experience the miscarriage of one twin.


Due to technology and early ultrasounds this is more widely known. It is likely to happen just as often now as it did before we had the technology of early ultrasounds.

Does a vanishing twin harm the surviving twin and/or mother?

Surviving Twin: In most cases, as long as the surviving twin is healthy, he/she will have no problems and will continue through to a healthy delivery. If the twin dies during the second or third trimester there is a higher risk of cerebral palsy and sometimes the fetus will reabsorb practically into the surviving twin.


Mother: The mother will be emotionally confused with devastation for the loss one baby and survival of the other. Physically, if the vanishing twin occurred during the first trimester the mother will have no issues. By the second or third trimester there may be some complications during pregnancy such as preterm labor or infection.

How is vanishing twin syndrome diagnosed?

When a mother has an ultrasound early on in pregnancy around five to seven weeks, she will discover she is having twins. At the next visit only one heartbeat can be heard, an ultrasound confirms only one fetus. This is devastating for mother to be and family members.

Other expectant mothers will have symptoms of a miscarriage, bleeding and cramping. But an ultrasound would show a healthy growing single baby; this could imply there was more than one baby.


The diagnosis of VTS before advancement in technology was to examine the placenta after delivery. Due to ultrasounds a vanishing twin can be realised during early pregnancy.

What causes a vanishing twin?

It’s unclear why exactly a vanishing twin occurs though it has been said to happen more often in an older mother. Nutritional, embryo attachment and/or abnormalities with the fetus could also be factors.

One thing which is certain is that a vanishing twin is not the fault of the mother or anyone else. You could also experience the same twin pregnancy signs and symptoms as other mother’s in labor, so there is no real way to determine a prognosis for a vanishing twin

Is treatment required for vanishing twin syndrome?

When VTS usually happens in the first trimester, mother and baby will probably not need any type of medical care, going on to have a normal single baby pregnancy.


If the vanishing twin occurs during the second or third trimester a doctor will treat as appropriate. Preterm labor or infection may be of concern.

Dealing with Grief
Every mother who goes through the experience of a vanishing twin will deal with their grief in their own way. Other expectant mothers will not know they were having twins. Talk with your healthcare provider if you need support.

For our more detailed Frequently Asked Questions – please refer to our Twins FAQ

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