What is the rarest form of conjoined twins? (2023)

The rarest form of conjoined twins is monocephalic conjoined twins, which occurs in only one in every 2. 5 million live births. Monocephalic conjoined twins, also known as “dicephalic parapagus,” is a condition where two babies are born as a single body with two heads and one body.

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The twins typically share a thorax, abdomen, pelvis, circulatory system, and parts of the nervous system. Monocephalic conjoined twins typically do not survive long after birth due to life-threatening complications.

In extremely rare cases, some babies have survived for some months with proper medical care. In such cases, extensive research has been conducted to understand the medical implications and possible medical interventions one could take to help them live long and healthy lives.


  • What type of conjoined twins Cannot be separated?
  • Has there ever been conjoined triplets?
  • Do conjoined twins have 2 private parts?
  • How rare is it to have conjoined triplets?
  • What happens if one conjoined twin commits a crime?
  • Do both conjoined twins have control over the body?

What type of conjoined twins Cannot be separated?

The types of conjoined twins that cannot be separated depend upon the nature of the shared organs, tissues, and other parts of their anatomy. Some twins may have joined organs, such as their heart or circulatory system, making any attempt at separation extremely risky.

(Video) Most Severe Cases of Conjoined Twins

Other times, a single organ or body part is shared, such as an arm, that cannot be separated without significant risk to both individuals. In some cases, the risk of separation is so great that medical personnel may deem it too dangerous and will recommend against attempting a separation surgery.

As a result, conjoined twins must learn to manage their disabilities and live as optimally as possible with their condition.

Has there ever been conjoined triplets?

Yes, conjoined triplets have been reported throughout medical history. The most famous case was the Binder triplets, three girls born in Germany in 1925 with two of them sharing the same torso and limbs.

The Binder triplets were only the fourth case of conjoined triplets to be recorded and were the first to survive past infancy. They spent most of their lives in an institution, as their condition made living at home difficult.

Through multiple operations, the doctors at the institution were eventually able to separate the sisters, whose names were Louise, Christine, and Marta, in 1933. Though the surgeries were a success, the Binder sisters did not have the easiest of lives and went through a variety of physical and psychological difficulties.

Do conjoined twins have 2 private parts?

Conjoined twins have an individual set of reproductive organs, so the answer is yes, they have two private parts. Conjoined twins are formed at the same time when a single fertilized egg (zygote) fails to separate properly in the womb.

(Video) 6 Types of Twins That Are Extremely Rare

In some cases, the egg only partially separates, creating twins that are conjoined at any area of the body. Though the twins may share some organs and limbs, they still have their own set of reproductive organs.

This means that conjoined twins can each experience the characteristics of their sexuality, such as arousal and desire, independently from their twin. However, depending on the exact location of where they are joined and how developed their mutual organs are, their private parts can be joined together.

How rare is it to have conjoined triplets?

It is incredibly rare to have conjoined triplets. According to research, the overall incidence of conjoined twins is estimated to be 1 in 200,000 to 1 million births, while the incidence of conjoined triplets is reported to be 1 in 50 million.

The actual number of conjoined triplets may be higher, however, due to increased survival rates in recent years due to advances in medical technology and treatment. Generally, approximately 75 percent of conjoined twins are female, and the majority of conjoined triplets are usually male or female triplets.

Conjoined triplets occur when three embryos become conjoined during the early stages of fetal development. The embryos do not necessarily have to be identical for this to occur. The type of conjoinment is determined by where in the body the structures are connected: cranial-caudal (head-to-tail), thoracopagus (chest-to-chest), pygopagus (buttocks-to-buttocks), ischiopagus (hip-to-hip) or diamniotic-dichorionic, which is unrelated to any anatomical region.

The rarity of conjoined triplets makes it difficult for researchers to understand the exact cause of this extremely rare occurrence. Factors such as genetics, environmental factors, and the mother’s health during pregnancy may play a role.

In most cases, conjoined triplets either miscarry naturally, or are separated through a medical procedure. If the infants are not treated, their quality of life can be poor and their life span may be shorter than normal.

Overall, though conjoined triplets are very rare, cases are growing across the world. To this day, the exact cause behind the birth of conjoined triplets remains mostly a mystery.

(Video) Rare surgery to separate conjoined twins

What happens if one conjoined twin commits a crime?

It depends on the jurisdiction, as the laws will vary from country to country on what happens if one conjoined twin commits a crime. In general, each conjoined twin is viewed as a separate individual under the law, so one twin could be held liable for a crime in the same way any other individual would be, separate from their conjoined twin.

For example, if one conjoined twin were to commit a criminal offense such as robbery, the criminal justice system would need to determine whether that particular twin had the capacity for criminal intent, and would be liable for the crime.

In some states, the outcome of a case in which one conjoined twin is accused of a crime can depend on the state of mental health of the twins. If it can be established that one twin was acting without any mental capacity due to disability, they may not be held liable as any other individual would.

Conversely, some jurisdictions have also acknowledged that although one conjoined twin can be held legally responsible for a criminal act, it is conceivable that the other twin could also have some degree of responsibility, depending on the level of cognitive and physical control the two had within their conjoined form.

Ultimately, responsibility for any crime one conjoined twin may commit is likely to be assessed on a case-by-case basis, and the outcome will depend on a variety of complex factors.

Do both conjoined twins have control over the body?

The answer to this question is different depending on the particular case of each conjoined twin. Generally speaking, each twin has its own distinct limbs, heart, lungs and brain, which means they also have independent control of their respective bodies.

(Video) The Incredible Conjoined Twins Attached At The Head | BORN DIFFERENT

However, in some cases, the twins can be joined at the brain, spine or skull, which can lead to a situation where the twins share some sort of physical control, often in the form of coordination of movement.

It can be the case that each twin independently initiates movement with their own body, or that one of the twins will initiate the movement and the other will follow. It is important to mention that this does not always mean that both twins involved in a joined body are affected in the same way.

Quite often, due to differences in anatomy, one twin may be able to move more freely than the other. Ultimately, it is important to consider the individual case of each twin when trying to answer this question.


What conjoined twins Cannot be separated? ›

Approximately 75 percent of conjoined twins are joined at least partially in the chest and share organs with one another. If they have separate sets of organs, chances for surgery and survival are greater than if they share the same organs. As a rule, shared heart conjoined twins cannot be separated.

Has there ever been conjoined triplets born? ›

A possible fourth case of conjoined triplets, that lived for 2 h, was reported to have been born in Samsun, Turkey in the 1950s, with three heads, four arms and four legs (Anonymous., 1954). At autopsy, two hearts, four lungs, and three livers were found.

Can conjoined twins be 2 genders? ›

The craniopagus twins have separate bodies but partially fused skulls, and share bone, vital blood vessels and 30% of their brain (the frontal lobe and the parietal lobe).

What conjoined twins had a baby? ›

Now an adult, she just had her own baby. Charity and Kathleen Lincoln were conjoined at the torso when they were born more than two decades ago. They were connected at the sternum and shared several vital internal organs that were intertwined.

Can conjoined twins have different fathers? ›

Is this even possible? If so, how would the genetics work for the conjoined baby? First off, yes, it is possible for twins to have different fathers. This goes by the exciting name heteropaternal superfecundation.

Can conjoined twins be pregnant? ›

Of all the female conjoined twin sets either documented by medical authorities or referenced in ancient literary sources, in only one case were pregnancy and delivery successfully achieved by the conjoined twins themselves.

What is the oldest living conjoined twins? ›

Conjoined Twins. confounded everyone in living to the ripe old age of 68. hugely fulfilling life.

Do conjoined twins have a short lifespan? ›

The overall survival rate of conjoined twins is from 5% to 25%, with about 75% of surgical separations resulting in at least one twin surviving. Approximately 200 pairs of conjoined twins are born alive each year, and about half die before their first birthday.

What is a parasitic twin? ›

A parasitic twin is a type of conjoined twin where one fetus stops developing but remains attached to its twin. The other twin continues to develop, but is usually born with the limbs, organs or other tissue structures from its parasitic twin still attached. It's a very rare condition. Appointments 216.444.6601.

Can a baby have two fathers? ›

Although this is quite rare it can happen and it's called superfetation. Two babies are conceived from separate acts in two different cycles. These babies can be from the same father or two different men. When heteropaternal superfecundation occurs, the babies are from different fathers.

Do conjoined twins share private parts? ›

While conjoined twins are typically classifi ed by the point of fusion, for our purposes, they may be divided into two broad categories: homogenitally conjoined twins, who shared a single set of genitalia, and heterogenitally conjoined twins, with two distinct sets of genitalia.

What is a chimera twin? ›

Chimerism occurs when a woman is pregnant with twins and one embryo dies, and the other embryo absorbs the twin's cells. (Scientifically speaking, this type of chimerism is called tetragametic because the baby was derived from four gametes – one egg and one sperm for each embryo.)

What happens to one conjoined twin when the other dies? ›

To your question, Dr. Eric Strauch, a pediatric surgeon at the University of Maryland Hospital for Children, says simply, "They die." Once the dead twin's heart stops, he adds, the "blood stops pumping, the vessels dilate, and the conjoined twin will essentially bleed into the dead twin.

What happens when one of the conjoined twins dies? ›

When one of the conjoined twins dies, usually the surviving twin follows in that twin's footsteps, whether from natural causes or an unintended catastrophe. Conjoined twins can split apart over the course of a few hours or even several days, but once they do, the surviving twin has a limited lifespan.

Can conjoined twins sleep? ›

Conjoined twins with a common heart system and circulatory system were observed during the 14th and 15th days for 11 hr. Sleep, Waking, and Quiet and Active Sleep were recorded in minute intervals. Clear independence of sleep and waking was manifest, and total independence of Quiet and Active sleep was noted.

What are polar twins? ›

Polar twins. Polar twins share the same chromosomes from their birthing parent, but they get different chromosomes from their non-birthing parent. This is because they're created from a single egg but two separate sperm.

Do conjoined twins have the same fingerprints? ›

In fact, the National Forensic Science Technology Center states that, “no two people have ever been found to have the same fingerprints — including identical twins.” Also, it's important to keep in mind that fingerprints also vary between your own fingers — this means you have a unique print on each finger.

Which parent decides twins? ›

However, for a given pregnancy, only the mother's genetics matter. Fraternal twins happen when two eggs are simultaneously fertilized instead of just one. A father's genes can't make a woman release two eggs.

At what age are conjoined twins separated? ›

Usually, twins have separation surgery in the first 3 months to 12 months of life. The success of the separation surgery depends on many factors, mainly where the twins are connected and which structures they share.

Can conjoined twins be one male and one female? ›

Conjoined twins are monochorionic (one placenta) and monoamniotic (one amniotic sac). Conjoined twins exist in a female to male ratio of 3 to 1.

Why are most conjoined twins female? ›

Experts don't know exactly what causes the condition. But it likely involves splitting or fusion of very early-stage embryos soon after fertilization. All conjoined twins are identical, and about two-thirds are assigned female at birth (AFAB).

Did the conjoined twins ever get married? ›

The best example of this would probably be the story of Chang and Eng Bunker, the “Siamese Twins,” so called because they were from Siam (now Thailand). Chang and Eng were joined by just a bit of liver and some skin. One April day in 1843, Chang married Adelaide Yates, while brother Eng married sister Sallie Yates.

Is Ronnie and Donnie the conjoined twins still alive? ›

Ronald Lee Galyon and Donald Lee Galyon (October 28, 1951 – July 4, 2020) were conjoined twins.
Ronnie and Donnie Galyon
DiedJuly 4, 2020 (aged 68) Dayton, Ohio
Occupation(s)Sideshow attractions, reality TV personalities
Known forOldest set of conjoined twins
1 more row

Did Brittany and Abby ever get separated? ›

As the twins grew and learned to walk and develop other skills, their parents confirmed their decision against separation, arguing that the quality of life for the surviving twin or twins living separately would be less than their quality of life as conjoined people.

How old can conjoined twins live? ›

Ronnie and Donnie Galyon of Ohio (1951–2020), omphalopagus; longest-lived conjoined twins in the world at 68 years and 250 days.

Do conjoined twins have different Social Security numbers? ›

Conjoined twins are still distinct individuals, with their own birth certificate and social security number.

Do Abby and Brittany have two stomachs? ›

The Hensel twins, Abby and Brittany, were born in March, 1990. They are called dicephalus conjoined twins. They have separate hearts and stomachs, one pair of arms and one pair of legs. Their spines join at the pelvis and they have only one set of organs from the waist down.

What is an evil twin called? ›

Type of doppelgänger

In modern use, evil twin and one sense of the word doppelgänger have come to be virtually interchangeable.

What is an invisible twin? ›

Vanishing twin syndrome was first recognized in 1945. This occurs when a twin or multiple disappears in the uterus during pregnancy as a result of a miscarriage of one twin or multiple. The fetal tissue is absorbed by the other twin, multiple, placenta or the mother. This gives the appearance of a “vanishing twin.”

What is a pseudo twin? ›

Pseudo-twins can form in ordered structures under high stress conditions. These twins are defined by lattice sites that are at twin positions but are incorrectly occupied by different species of atoms.

What is super pregnancy? ›

Overview. Superfetation is when a second, new pregnancy occurs during an initial pregnancy. Another ovum (egg) is fertilized by sperm and implanted in the womb days or weeks later than the first one. Babies born from superfetation are often considered twins since they may be born during the same birth on the same day.

Do you carry your baby daddy DNA for 7 years? ›

Male fetal progenitor cells persist in maternal blood for as long as 27 years postpartum.

Can twins be born on different days? ›

For the most part, twins and multiples share the same birthday. However, depending on the time of day the babies are born and how long the timespan is between each baby's birth, twins can be born on different days.

How do conjoined twins make love? ›

With parapagus twins, there's typically a “red line” that separates feeling on both sides — until you get to the waist area. More bluntly, you would be having sex with a shared sexual organ, which usually means that both will experience the same orgasm at the same time.

How much does it cost to separate conjoined twins? ›

But they do come at a price, even if it is not made public. Judging from other separations of conjoined twins, the Salinas Fierros' surgery alone could approach $1 million or more. Months, perhaps years, of aftercare could push the bill much higher.

What is the survival rate of conjoined twins? ›

Conjoined twins generally have a poor prognosis. The total survival rate is 7.5%. Only 60% of the surgically separated cases survive.

What famous person has chimerism? ›

Lydia Fairchild (born 1976) is an American woman who exhibits chimerism, having two distinct populations of DNA among the cells of her body.

Who are the Sesquizygotic twins? ›

The twins, who are identical on their mother's side but share only part of their father's DNA, are the first case of semi-identical, or sesquizygotic, twins identified in Australia. They are the first worldwide to be diagnosed by genetic testing while still in the womb.

What causes a vanishing twin? ›

Vanishing twin syndrome (VTS) is a miscarriage that causes a pregnancy involving twins to become a pregnancy involving one baby. It occurs when one of the embryos detected during an ultrasound stops developing. VTS can't be treated or prevented.

What happens if a Siamese twin commits a crime? ›

As a result, they could be sentenced to prison, but only for the lesser crime committed by Dot. In California, that would mean the twin's maximum sentence would be 3 years in prison for being an accessory, a far cry from the possible life sentence Dot could get for murder.

What organs did Ronnie and Donnie Galyon share? ›

Born on October 28th, 1951 in Dayton, Ohio, the twins — known as Ronnie and Donnie — weighed a combined 11 pounds and 11 ounces at birth and were joined at the abdomen. Each brother had his own set of arms and legs, as well as an individual stomach, small intestine, and kidneys.

How do conjoined twins use the bathroom? ›

If conjoined twins share genitals, then they go to the bathroom together when they need to go. If they have separate genitals, one will have to squat or lean over while the other one uses the restroom. It's also possible for conjoined twins to use bedpans or have a bathroom specially built to accommodate their needs.

Have there ever been conjoined triplets? ›

In a previous review of the literature, only 3 cases of true conjoined triplets have been found. However, all 3 cases occurred in the 19th or early 20th century. 3, 4, 5 Because conjoined triplets are rare, there is no classification system for this disorder.

Can Abby and Brittany have babies? ›

Can Brittany and Abby have babies? Yes, they can.

Can conjoined twins be imprisoned? ›

This is literally one of those things that never happens. But if it did, the twin could be charged as an accomplice, because they knew of and didn't stop the crime. If they can't be separated, then they both will serve some modified term of imprisonment.

Which conjoined twins Cannot be separated? ›

Approximately 75 percent of conjoined twins are joined at least partially in the chest and share organs with one another. If they have separate sets of organs, chances for surgery and survival are greater than if they share the same organs. As a rule, shared heart conjoined twins cannot be separated.

Who are the conjoined twins who died? ›

A conjoined twin has died during a procedure intended to separate the two 19-month-old boys. The two boys, Yusuf and Yassin, are from Yemen, a Middle Eastern country located on the southern end of the Arabian Peninsula that has been devastated by years of civil war.

Is being a conjoined twin a disability? ›

In fact, many conjoined twins do not consider themselves disabled, although Dreger believes that people with unusual anatomies should be considered so, even if they do not have impairment in the customary physical sense.

Why weren t Carmen and Lupita separated? ›

When Lupita and Carmen were young, doctors considered separating them, but concluded it couldn't be done safely because they shared too many vital organs and their lower spine. Carmen says: “We're never going to get separated.

Why were Carmen and Lupita not separated? ›

Lupita and Carmen revealed that they are connected at the torso, where they share a pelvis and reproductive system. The women have two separate hearts and stomaches, despite their digestive tracks being shared. At the age of four, they were told that they could not be separated.

Can the Hogan twins be separated? ›

Krista and Tatiana Hogan were born October 25, 2006, in Vancouver, B.C. A CT scan of the twins showed they could never be separated due to the risk of serious injury or death. The structure of the twins' brains makes them unique in the world.

Can some conjoined twins be separated? ›

Some surviving conjoined twins can be surgically separated. The success of surgery depends on where the twins are joined and how many and which organs are shared. It also depends on the experience and skill of the surgical team.

Who controls Carmen and Lupita legs? ›

Carmen and Lupita Andrade, 22, are attached along their chest walls. They have two arms, but only a single leg each, with Carmen controlling the right leg, and Lupita managing the left.

Were Brittany and Abby ever separated? ›

As the twins grew and learned to walk and develop other skills, their parents confirmed their decision against separation, arguing that the quality of life for the surviving twin or twins living separately would be less than their quality of life as conjoined people.

Are conjoined twins sad news Abby and Brittany pregnant? ›

Are Abby and Brittany Hensel pregnant? These are the rumours that have been circulating in the media. However, the conjoined twins are not having a baby anytime soon because none of them is pregnant.

Who were the longest living conjoined twins? ›

Conjoined Twins. confounded everyone in living to the ripe old age of 68. hugely fulfilling life.

Who controls the body Abby and Brittany? ›

With two sets of lungs, two hearts, two stomachs, one liver, one large intestine and one reproductive system, they have learned from a young age to co-ordinate their body, with Abby controlling the right hand side and Brittany the left.

Do Carmen and Lupita have boyfriends? ›

Despite their condition, the twins said that "their own sides are their own sides". Lupita said that she is "asexual and aromantic", while Carmen said that she has been dating her boyfriend, Daniel, for about a year and a half. We're Conjoined Twins.

What happens to Siamese twins when one dies? ›

To your question, Dr. Eric Strauch, a pediatric surgeon at the University of Maryland Hospital for Children, says simply, "They die." Once the dead twin's heart stops, he adds, the "blood stops pumping, the vessels dilate, and the conjoined twin will essentially bleed into the dead twin.

Has there ever been a 2 headed person? ›

On December 19, 2011, a pair of male twins, Emanoel and Jesus Nazare, were born in Marajó Island, Brazil. The children had two heads, two legs and two arms, sharing all the body below the neck. Each child had a separate spine, but shared a heart, liver, lungs and pelvis, and both brains functioned.

Which conjoined twins died after separation? ›

The separation stage of the surgery was completed at SST 13:30, but there was significant blood loss during the blood vessel repairing process, and Ladan Bijani died at around 14:30 on the operating table; her sister Laleh Bijani died 90 minutes later.

What is the life expectancy of conjoined twins? ›

The overall survival rate of conjoined twins is from 5% to 25%, with about 75% of surgical separations resulting in at least one twin surviving. Approximately 200 pairs of conjoined twins are born alive each year, and about half die before their first birthday.


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