All You Ever Wanted to Know About Parasitic Twins

Cases of parasitic twins are rare and fascinating to learn about. There’s much to understand! If you’re looking to do some research, this is the article for you.

We’re going to discuss what a parasitic twin is, as well as highlight a famous example of parasitic twins. By the end of this article, we hope you’ll have a good understanding of this interesting topic.

Do prepare yourself, as this article discusses the medical nature of parasitic twins.

What is a Parasitic Twin?

A parasitic twin is a specific type of conjoined twin. During the gestation period, one of the two fetuses ceases development and becomes a vestigial parasitic twin to the fully developed twin.

This means that the underdeveloped twin is partially absorbed into the dominant twin. This dominant twin is also known as the autositic twin or autosite.

We call the underdeveloped twin parasitic rather than conjoined. This is because it has formed incompletely and is wholly dependent on the fully developed bodily functions of the autosite. The parasitic twin appears as asymmetrical, nonconscious tissue, or extra limbs, on the autositic twin.

Below is a photograph of Frank Lentini, who used his extra leg to become a famous sideshow performer.

The many different variations of parasitic twins. They get their names based on how they join the dominant twin. These include:

Cephalopagus

The parasitic twin is joined to the dominant one on the side of the head. This is different from craniopagus parasiticus, which we will discuss later on this list. Sadly, the life expectancy of babies with this condition is low. This is because malformations in the brain are a very common occurrence.

Epigastric

Twins are joined at the upper abdomen. Depending on which extremities join with the autosite, the life expectancy can vary. Heart failure and other heart defects are unfortunately common.

Omphalopagus

In this variation, twins are joined at the lower abdomen. The life expectancy is not as low as in epigastric cases, as the heart is not involved. However, there is still a risk to organs like the liver, diaphragm, and the digestive system.

Craniopagus Parasiticus

In this case, twins are joined at the skull or cranium. Unlike cephalopagus cases, this variation results in a second parasitic head attached to the dominant head. Similar to cephalopagus cases, babies with this condition have a low life expectancy. This is due to the possibility of a neurological deficit.

At the top of this article, you will have seen a sketch of the ‘Two-Headed Boy of Bengal’. This is a famous case of craniopagus parasiticus.

Ischiopagus

The parasitic twin is joined to the dominant one at the pelvis. Like the omphalopagus variation, organs like the liver are at risk of damage. Genital functions are often impaired.

Parapagus

In this variation, twins are joined at the sides and pelvis. With conjoined twins, this results in having a combined torso while sharing a pelvis.

In cases involving a parasitic twin, the autositic twin might have extra limbs or other unrecognizable protrusions in those regions instead.

Pygopagus

Twins are joined at the lower spine. This can prove very dangerous for spinal cord development and can impair the use of sexual organs. Babies with this condition are likely to suffer other developmental issues as they grow up.

Rachipagus

Twins in this case are joined at the back. This usually results in a fusion of the vertebral arches, as well as the soft tissue along the back. The parasitic twin can cause complications with spinal development, particularly with a variation like lower spine rachipagus.

Thoracopagus

In this variation, twins are joined at the upper chest. This variation always involves the heart. Unfortunately, attempting to fully separate the parasitic twin is dangerous. This is due to the possibility of heart failure.

Photo credit: Wikimedia

How are Conjoined Twins Different From Parasitic Twins?

Conjoined twins are, at least as far as modem science can determine, the result of what we call fission. The fission theory states that the fertilized egg splits partially, resulting in the twins not being fully separate. This results in an anatomical connection between the twins. This condition is rare.

As explained previously, a parasitic twin forms in a different way. This condition is also extremely rare. Parasitic twinning occurs during gestation. One twin joins with a host twin in such a way that the host twin becomes a vestigial structure.

Parasitic twins are unable to survive independently from the healthy twin. A parasitic twin is nonconscious and can appear as incompletely formed body parts or additional limbs.

For example, the autositic twin may have an additional lower extremity, such as extra legs or even just one extra right leg. These extremities are not fully formed.

How is a Vestigial Twin Diagnosed?

The presence of a parasitic twin is diagnosed during a twin pregnancy thanks to ultrasound imaging tests.

These tests use sound frequencies. They project sound and record the waves that echo back to see a baby in the womb - similar to how a bat uses echolocation. These sounds are higher than what the human ear can hear and are harmless to the twins.

Are Parasitic Twins Alive and Conscious?

In almost all cases, no. A parasitic twin is nonconscious, and cannot survive without the functions of the other twin. In that regard, it is not considered alive. A parasitic twin only functions as an extension of the dominant twin. In some cases, the parasitic twin only manifests as an extremity on the body of the surviving twin.

Famous Parasitic Twins

Parasitic twins often get treated as medical curiosities instead of people. As such, many famous parasitic twins were seen as attractions and paraded by people like PT Barnum.

Barnum ran a circus and museum that ridiculed people who were deemed different. He was guilty of several human rights violations by today’s standards. The first parasitic twin in Barnum’s circus was George Lippert.

*George Lippert - Photo credit:* *Wikimedia*

There are a few examples of parasitic twins who lived successful lives despite the challenges life threw their way. History remembers Betty-Lou Williams as the ‘highest-paid human oddity,’ although that phrase is potentially reductive.

It is true, however, that Williams amassed a considerable fortune, due to the parasitic twin which had from the left side of her body.

On top of purchasing a 260-acre ranch for her parents, she also put all eleven of her siblings through college. She died at only 23 but is remembered for her charisma and kindness.

*Betty-Lou Williams - Photo credit:* *Kentake Page*

Conclusion

Parasitic twins are a fascinating topic of discussion. While it’s true that life expectancy is short and the risk of medical complications is high, it isn’t all doom and gloom.

The stories of those who lived successful lives despite societal stigmas and physical challenges should inspire us. We hope you’ve benefited from learning everything you ever wanted to know about parasitic twins.

For more inspiring stories of truly unique people, check out Phreeque.com.