Useful? Share it!

Vanishing Twin Syndrome

vanishing twin

What is a vanishing twin?

When you conceive twins or multiples, sometimes one of the foetuses isn’t as strong, and you miscarry that foetus. The other/s are still healthy, so the pregnancy continues, but that foetus does not pass out of the body – it is reabsorbed into either the placenta, the mother, or the other foetus/es. This is called vanishing twin syndrome. Roughly 21-30% of multi pregnancies will have vanishing twin syndrome occur.

How do you know if you’ve had a vanishing twin?

The twin that disappears, or “vanishes” will show up on an early ultrasound – in the first trimester. If you have any ultrasounds in the first trimester that show a twin, then later in the pregnancy, there is no twin to be found, it is likely that this was a vanishing twin that has been reabsorbed.

Sometimes the mother will experience miscarriage symptoms, though the remaining foetus will still be healthy.

Many times, though, the mother will never know she was carrying multiples if she doesn’t have an ultrasound early enough to detect them both before one vanishes.

Why does it happen?

Most of the time, the cause is unknown – though it is more likely an abnormality from the point of conception rather than anything that happens later. Upon analysis after birth, the abnormalities usually found are chromosomal – though the surviving baby is fine. It is more likely to happen in pregnancies for older women, though there are usually no warning signs or things to look out for that might be cause for concern before the loss of one twin actually occurs.

Is there any treatment needed?

In most cases, the mother and remaining foetus will be fully healthy, so no treatment is required. There is the possible risk of mental symptoms such as feelings of grief, loss, and confusion between grieving for the lost foetus and relief or even excitement that the other is still healthy. There can also be feelings of disappointment if the mother was particularly excited for a multi pregnancy, and ends up with a singleton instead. Some mothers may need psychological help to deal with these emotions, while her physical health stays fine.

There is a chance that the smaller foetus could die later in the pregnancy, which can cause health complications like preterm labour, infection, or haemorrhaging. Medical treatment would be required for any of those instances, but not for early term occurrences of a vanishing twin.

For the remaining baby, if the twin dies later in the pregnancy, there is a slight chance that not all of the foetus will be reabsorbed. An unusual side effect is a teratoma tumour growing somewhere on the other foetus’s body containing matter left from the twin. These are usually benign, and depending on the position and size, can be removed once the baby is born.

There are support groups specifically for those who have experienced vanishing twin syndrome, as well as for people who have grown up without their twin. On occasion, the surviving twin feels guilt, grief, or longing for the sibling they lost.

Post your comment

Comment Guidelines : Play nice! We welcome opinions, discussion and compliments. Especially compliments. But remember: the person on the other side of the computer screen is someone's mum, brother, nan or highly intelligent but opinionated cat. We don't tolerate nastiness or bullying. We'll delete disrespectful comments and any replies to them. more

Your email address will not be published. Required fields are marked *

If you have a Gravatar, it will appear next to your comments. Read more about Gravatars here


Prove you're human.. *

Free weekly newsletters | Sign up now!
who are these people who write great posts? meet our hubbub authors!
Learn how you can contribute to the hubbub!

learn how you can become a reviewer!


forum - chatting now

Pregnant for the first-time?

Not sure where to start? We can help!

Our Insider Programs for pregnancy first-timers will lead you step-by-step through the 14 Pregnancy Must Dos!