Conjoined twins, popularly referred to as Siamese twins, are
twin
Twins are two offspring produced by the same pregnancy.MedicineNet > Definition of Twin Last Editorial Review: 19 June 2000 Twins can be either ''monozygotic'' ('identical'), meaning that they develop from one zygote, which splits and forms two ...
s joined ''
in utero''. It is a very rare phenomenon, estimated to occur in anywhere between one in 50,000 births to one in 200,000 births, with a somewhat higher incidence in southwest Asia and Africa.
Approximately half are
stillborn, and an additional one-third die within 24 hours. Most live births are female, with a ratio of 3:1.
Two possible explanations of the cause of conjoined twins have been proposed. The one that is generally accepted is ''fission'', in which the fertilized egg splits partially.
The other explanation, no longer believed to be accurate,
[ is ''fusion'', in which the fertilized egg completely separates, but ]stem cell
In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can change into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of cell ...
s (that search for similar cells) find similar stem cells on the other twin and fuse the twins together. Conjoined twins and some monozygotic
Twins are two offspring produced by the same pregnancy.MedicineNet > Definition of Twin Last Editorial Review: 19 June 2000 Twins can be either ''monozygotic'' ('identical'), meaning that they develop from one zygote, which splits and forms two e ...
, but not conjoined, twins share a single common chorion
The chorion is the outermost fetal membrane around the embryo in mammals, birds and reptiles (amniotes). It is also present around the embryo of other animals, like insects and molluscs.
Structure
In humans and other therian mammals, the cho ...
, placenta
The placenta (: placentas or placentae) is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas, and waste exchange between ...
, and amniotic sac
The amniotic sac, also called the bag of waters or the membranes, is the sac in which the embryo and later fetus develops in amniotes. It is a thin but tough transparent pair of biological membrane, membranes that hold a developing embryo (and l ...
'' in utero''.
Chang and Eng Bunker
Chang Bunker (จัน บังเกอร์) and Eng Bunker (อิน บังเกอร์) (May 11, 1811 – January 17, 1874) were Siamese (Thai)-American conjoined twins, conjoined twin brothers whose fame propelled the expression " ...
(1811–1874) were brothers born in Siam (now Thailand) who traveled widely for many years and were known internationally as the Siamese Twins. Chang and Eng were joined at the torso by a band of flesh and cartilage, and by their fused livers. In modern times, they could easily have been separated. Due to the brothers' fame and the rarity of the condition, the term ''Siamese twins'' came to be associated with conjoined twins.
Causes
There are two hypotheses about the development of conjoined twins.
# a single fertilized egg does not fully split during the process of forming identical twins. If the zygote division occurs after two weeks of the development of the embryonic disc, it results in the formation of conjoined twins.
# fusion of two fertilized eggs occurs early in development.
Partial splitting of the primitive node
The primitive node (or primitive knot) is the organizer for gastrulation in most amniote embryos. In birds, it is known as Hensen's node, and in amphibians, it is known as the Spemann-Mangold organizer. It is induced by the Nieuwkoop center in ...
and streak may result in the formation of conjoined twins. These twins are classified according to the nature and degree of their union. Occasionally, monozygotic twins are connected only by a common skin bridge or by a common liver bridge. The type of twins formed depends on when and to what extent abnormalities of the node and streak occurred. Misexpression of genes, such as goosecoid, may also result in conjoined twins. Goosecoid activates inhibitors of BMP4
Bone morphogenetic protein 4 is a protein that in humans is encoded by ''BMP4'' gene. BMP4 is found on chromosome 14q22-q23.
BMP4 is a member of the bone morphogenetic protein family which is part of the transforming growth factor-beta superfami ...
and contributes to regulation of head development. Over- or underexpression of this gene in laboratory animals results in severe malformations of the head region, including duplications, similar to some types of conjoined twins.
Types
Conjoined twins are typically classified by the point at which their bodies are joined. The most common types of conjoined twins are:
* ''Thoracopagus'' (28% of cases):[ Two bodies fused from the upper chest to the lower chest. These twins usually share a ]heart
The heart is a muscular Organ (biology), organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrie ...
and may also share the liver
The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...
or part of the digestive system
The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder). Digestion involves the breakdown of food into smaller and smaller compone ...
. Survival rate is poor.
* ''Thoraco-omphalopagus'' (18.5%):[ Two bodies fused from the upper chest to lower belly. The heart is always shared in these cases.][ , twins who share a heart have not been able to both survive separation; a designated twin who is allotted the heart may survive if the other twin is sacrificed.
* ''Omphalopagus'' (10%):][ Two bodies fused at the lower abdomen. Unlike thoracopagus, the heart is not shared; however, the twins often share a liver, a digestive system, a diaphragm and other organs.][ Survival rate is 82%.]
* ''Heteropagus'' ( parasitic twin) (10%):[ Twins that are asymmetrically conjoined, resulting in one twin that is small, less formed, and dependent on the larger twin's organs for survival.
* '' Craniopagus'' (6%):][ Fused ]skull
The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate.
In the human, the skull comprises two prominent ...
s, but separate bodies. These twins' heads may be conjoined at the back, front, or side of the head, but not on the face or at the base of the skull.[ Survival rate is poor.]
Other, less common types of conjoined twins include:
* ''Cephalopagus'': Two faces on opposite sides of a single, conjoined head; the upper portion of the body is fused while the bottom portions are separate. These twins generally cannot survive due to severe malformations of the brain. This is also known as janiceps (after the two-faced Roman deity Janus
In ancient Roman religion and myth, Janus ( ; ) is the god of beginnings, gates, transitions, time, duality, doorways, passages, frames, and endings. He is usually depicted as having two faces. The month of January is named for Janus (''Ianu ...
).[
* ''Syncephalus'': One head with a single face but four ears and two bodies.][
* ''Cephalothoracopagus'': Bodies fused at the head and thorax, with two faces facing in opposite directions, or sometimes with a single face and an enlarged skull.][
* ''Xiphopagus'': Two bodies fused in the xiphoid cartilage, which extends approximately from the navel to the lower breastbone. These twins almost never share any vital organs, with the exception of the liver.][ A famous example is ]Chang and Eng Bunker
Chang Bunker (จัน บังเกอร์) and Eng Bunker (อิน บังเกอร์) (May 11, 1811 – January 17, 1874) were Siamese (Thai)-American conjoined twins, conjoined twin brothers whose fame propelled the expression " ...
.
* '' Ischiopagus'': Fused lower half of the two bodies, with spines conjoined end-to-end at a 180° angle. These twins have four arms; one, two, three or four legs; and typically one set of external genitalia
A sex organ, also known as a reproductive organ, is a part of an organism that is involved in sexual reproduction. Sex organs constitute the primary sex characteristics of an organism. Sex organs are responsible for producing and transporting ...
and one anus
In mammals, invertebrates and most fish, the anus (: anuses or ani; from Latin, 'ring' or 'circle') is the external body orifice at the ''exit'' end of the digestive tract (bowel), i.e. the opposite end from the mouth. Its function is to facil ...
.[ Survival rate is 63%.]
* ''Omphalo-Ischiopagus'': Fused in a similar fashion to ischiopagus twins, but facing each other, with a joined abdomen, akin to omphalopagus. These twins have four arms, and two, three, or four legs.[
* ''Parapagus'': Fused side by side with a shared ]pelvis
The pelvis (: pelves or pelvises) is the lower part of an Anatomy, anatomical Trunk (anatomy), trunk, between the human abdomen, abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also c ...
. Those that are ''dithoracic parapagus'' are fused at the abdomen and pelvis, but not at the thorax. Those that are '' diprosopic parapagus'' have one trunk and two faces. Those that are '' dicephalic parapagus'' have one trunk and two heads, and may have two (dibrachius), three (tribrachius), or four (tetrabrachius) arms.[ Survival rate is poor.]
* '' Craniopagus parasiticus'': Like craniopagus, but with a second bodiless head attached to the dominant head.
* ''Pygopagus'' or ''Iliopagus'': Two bodies joined at the pelvis.[ Survival rate is 68%.]
* ''Rachipagus'': Twins joined along the back of their bodies, with fusion of the vertebral arches and the soft tissue from the head to the buttocks. Twins of this type cannot be separated.
* ''Tricephalus'' (conjoined triplets): Extremely rare conjoining of 3 fetuses. Very few confirmed cases, both human and animal, are known.
Treatment
Separation
Surgery to separate conjoined twins may range from very easy to very difficult depending on the point of attachment and the internal parts that are shared. Most cases of separation are extremely risky and life-threatening. Though there have been a number of successful separations throughout history, in many cases, the surgery results in the death of one or both of the twins, particularly if they are joined at the head or share a vital organ. This makes the ethics
Ethics is the philosophy, philosophical study of Morality, moral phenomena. Also called moral philosophy, it investigates Normativity, normative questions about what people ought to do or which behavior is morally right. Its main branches inclu ...
of surgical separation, where the twins can survive if not separated, contentious. Alice Dreger of Northwestern University
Northwestern University (NU) is a Private university, private research university in Evanston, Illinois, United States. Established in 1851 to serve the historic Northwest Territory, it is the oldest University charter, chartered university in ...
found the quality of life of twins who remain conjoined to be higher than is commonly supposed. Lori and George Schappell and Abby and Brittany Hensel are notable examples.
The first recorded separation of conjoined twins took place in the Byzantine Empire
The Byzantine Empire, also known as the Eastern Roman Empire, was the continuation of the Roman Empire centred on Constantinople during late antiquity and the Middle Ages. Having survived History of the Roman Empire, the events that caused the ...
in the 900s. One of the conjoined twins had already died, so the doctors of the town attempted to separate the dead twin from the surviving twin. The result was briefly successful, as the remaining twin lived for three days after separation. The next recorded case of separating conjoined twins was several centuries later, in Germany, in 1689. The first recorded successful separation of conjoined twins was performed in 1689 by Johannes Fatio. Around this same time Dr. Böhm of Gunzenhausen separated his own children, a pair of omphalopagus or xiphopagus twins; the feebler twin died four days later, but the healthier one was still alive and well at age five, when the case was reported. In 1955, neurosurgeon Harold Voris (1902-1980) and his team at Mercy Hospital in Chicago performed the first successful operation to separate craniopagus twins (conjoined at the head), which resulted in long-term survival for both. The larger girl was reported in 1963 as developing normally, but the smaller girl was permanently impaired.
In 1957, Bertram Katz and his surgical team made international medical history performing the world's first successful separation of conjoined twins sharing a vital organ. Omphalopagus twins John Nelson and James Edward Freeman (Johnny and Jimmy) were born in Youngstown, Ohio, on April 27, 1956. The boys shared a liver but had separate hearts and were successfully separated at North Side Hospital in Youngstown, Ohio, by Bertram Katz. The operation was funded by the Ohio Crippled Children's Service Society.
Recent successful separations of conjoined twins include that of the separation of Ganga and Jamuna Shrestha in 2001, who were born in Kathmandu, Nepal
Kathmandu () is the capital and largest city of Nepal, situated in the central part of the country within the Kathmandu Valley. As per the 2021 Nepal census, it has a population of 845,767 residing in 105,649 households, with approximately 4 m ...
, in 2000. The 97-hour surgery on the pair of craniopagus twins was a landmark one which took place in Singapore; the team was led by neurosurgeons Chumpon Chan and Keith Goh. The surgery left Ganga with brain damage and Jamuna unable to walk. Seven years later, Ganga Shrestha died at the Model Hospital in Kathmandu in July 2009, at the age of eight, three days after being admitted for treatment of a severe chest infection.
Infants Rose and Grace Attard, conjoined twins from Malta, were separated in the United Kingdom by court order '' Re A'' over the religious objections of their parents, Michaelangelo and Rina Attard. The twins were attached at the lower abdomen and spine. The surgery took place in November 2000, at St Mary's Hospital in Manchester
Manchester () is a city and the metropolitan borough of Greater Manchester, England. It had an estimated population of in . Greater Manchester is the third-most populous metropolitan area in the United Kingdom, with a population of 2.92&nbs ...
. The operation was controversial because Rose, the weaker twin, would die as a result of the procedure as her heart and lungs were dependent upon Grace's. However, if the operation had not taken place, it was certain that both twins would die. Grace survived to enjoy a normal childhood.
In 2003, two 29-year-old women from Iran, Ladan and Laleh Bijani, who were joined at the head but had separate brains (craniopagus), were surgically separated in Singapore, despite surgeons' warnings that the operation could be fatal to one or both. Their complex case was accepted only because technologically advanced graphical imagery and modeling would allow the medical team to plan the risky surgery. However, an undetected major vein hidden from the scans was discovered during the operation. The separation was completed but both women died while still in surgery.
In 2019 Safa and Marwa Ullah were separated at Great Ormond Street Hospital
Great Ormond Street Hospital (informally GOSH, formerly the Hospital for Sick Children) is a children's hospital located in the Bloomsbury area of the London Borough of Camden, and a part of Great Ormond Street Hospital for Children NHS F ...
in London, England. The twins, born January 2017, were joined at the top of the head with separate brains and a cylindrical shared skull with the twins each facing in opposite directions to one another. The surgery was jointly led by neurosurgeon Owase Jeelani and plastic surgeon Professor David Dunaway. The surgery presented particular difficulties due to a number of shared veins and a distortion in the shape of the girls' brains, causing them to overlap. The distortion would need to be corrected in order for the separation to go ahead. The surgery utilized a team of more than 100 including bio engineers, 3D modelers and a virtual reality designer. The separation was completed in February 2019 following a total of 52 hours of surgery over three separate operations. The family returned to their home in Pakistan in October 2020, though one of the twins had a stroke during surgery which could make her unable to walk for the rest of her life.
History
The Moche culture of ancient Peru depicted conjoined twins in their ceramics dating back to 300 AD. Writing around 415 AD, St. Augustine of Hippo, in his book, '' City of God'', refers to a man "double in his upper, but single in his lower half—having two heads, two chests, four hands, but one body and two feet like an ordinary man."
According to Theophanes the Confessor, a Byzantine historian of the 9th century, around 385/386 AD, he writes that "in the village of Emmaus in Palestine
Palestine, officially the State of Palestine, is a country in West Asia. Recognized by International recognition of Palestine, 147 of the UN's 193 member states, it encompasses the Israeli-occupied West Bank, including East Jerusalem, and th ...
, a child was born perfectly normal below the navel but divided above it, so that it had two chests and two heads, each possessing the senses. One would eat and drink but the other did not eat; one would sleep but the other stayed awake. There were times when they played with each other, when both cried and hit each other. They lived for a little over two years. One died while the other lived for another four days and it, too, died."
In Arabia, the twin brothers Hashim ibn Abd Manaf
Hāshim ibn ʿAbd Manāf (; ), born ʿAmr al-ʿUlā (), was the great-grandfather of the Islamic prophet Muhammad and the progenitor of the ruling Banu Hashim clan of the Quraysh tribe in Mecca. At some point in his life before his father's deat ...
and 'Abd Shams were born with Hashim's leg attached to his twin brother's head. Legend says that their father, Abd Manaf ibn Qusai
Abd Manaf al-Mughirah ibn Qusai (, ''ʿAbd Manāf al-Mughīrah ibn Quṣayy'') was a Quraysh (tribe), Qurayshi and great-great-grandfather of the Islamic prophet Muhammad. His father was Qusai ibn Kilab, Quṣai ibn Kilāb.
Abd Manaf's name, mea ...
, separated his conjoined sons with a sword and that some priests believed that the blood that had flowed between them signified wars between their progeny (confrontations did occur between Banu al'Abbas and Banu Ummaya ibn 'Abd Shams in the year 750 AH).[The Life of the Prophet Muhammad: Al-Sira Al-Nabawiyya By Ibn Kathir, Trevor Le Gassick, Muneer Fareed, pg. 132] The Muslim polymath
A polymath or polyhistor is an individual whose knowledge spans many different subjects, known to draw on complex bodies of knowledge to solve specific problems. Polymaths often prefer a specific context in which to explain their knowledge, ...
Abū al-Rayhān al-Bīrūnī described conjoined twins in his book ''Kitab-al-Saidana''.[A. Zahoor (1997)]
Abu Raihan Muhammad al-Biruni
, Hasanuddin U
The English twin sisters Mary and Eliza Chulkhurst, who were conjoined at the back (pygopagus), lived from 1100 to 1134 (or 1500 to 1534) and were perhaps the best-known early historical example of conjoined twins. Other early conjoined twins to attain notice were the "Scottish brothers", allegedly of the dicephalus type, essentially two heads sharing the same body (1460–1488, although the dates vary); the pygopagus Helen and Judith of Szőny, Hungary (1701–1723), who enjoyed a brief career in music before being sent to live in a convent; and Rita and Cristina of Parodi of Sardinia
Sardinia ( ; ; ) is the Mediterranean islands#By area, second-largest island in the Mediterranean Sea, after Sicily, and one of the Regions of Italy, twenty regions of Italy. It is located west of the Italian Peninsula, north of Tunisia an ...
, born in 1829. Rita and Cristina were dicephalus tetrabrachius (one body with four arms) twins and although they died at only eight months of age, they gained much attention as a curiosity when their parents exhibited them in Paris.
Several sets of conjoined twins lived during the nineteenth century and made careers for themselves in the performing arts
The performing arts are arts such as music, dance, and drama which are performed for an audience. They are different from the visual arts, which involve the use of paint, canvas or various materials to create physical or static art objects. P ...
, though none achieved quite the same level of fame and fortune as Chang and Eng. Most notably, Millie and Christine McCoy (or McKoy), pygopagus twins, were born into slavery in North Carolina in 1851. They were sold to a showman
Showman can have a variety of meanings, usually by context and depending on the country.
Australia
Travelling Funfair, showmen ("showies") are people who run amusement and side show equipment at regional shows, state capital shows, events ...
, J.P. Smith, at birth, but were soon kidnapped by a rival showman. The kidnapper fled to England but was thwarted because England had already banned slavery. Smith traveled to England to collect the girls and brought with him their mother, Monimia, from whom they had been separated. He and his wife provided the twins with an education and taught them to speak five languages, play music, and sing. For the rest of the century, the twins enjoyed a successful career as "The Two-Headed Nightingale" and appeared with the Barnum Circus. In 1912, they died of tuberculosis
Tuberculosis (TB), also known colloquially as the "white death", or historically as consumption, is a contagious disease usually caused by ''Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can al ...
, 17 hours apart.
Giacomo and Giovanni Tocci, from Locana, Italy, were immortalized in Mark Twain
Samuel Langhorne Clemens (November 30, 1835 – April 21, 1910), known by the pen name Mark Twain, was an American writer, humorist, and essayist. He was praised as the "greatest humorist the United States has produced," with William Fau ...
's short story "Those Extraordinary Twins" as fictitious twins Angelo and Luigi. The Toccis, born in 1877, were dicephalus tetrabrachius twins, having one body with two legs, two heads, and four arms. From birth they were forced by their parents to perform and never learned to walk, as each twin controlled one leg (in modern times, physical therapy
Physical therapy (PT), also known as physiotherapy, is a healthcare profession, as well as the care provided by physical therapists who promote, maintain, or restore health through patient education, physical intervention, disease preventio ...
allows twins like the Toccis to learn to walk on their own). They are said to have disliked show business. In 1886, after touring the United States, the twins returned to Europe with their family. They are believed to have died around this time, though some sources claim they survived until 1940, living in seclusion in Italy.
Notable people
Born 19th century and earlier
*Mary and Eliza Chulkhurst, alleged names of the Biddenden Maids (per tradition, born in the 12th century) of Kent, England. They are the earliest set of conjoined twins whose names are (purportedly) known.
* Lazarus and Joannes Baptista Colloredo (1617 — after 1646), autosite-and-parasite pair
* Helen and Judith of Szony (Hungary, 1701 — 1723), pygopagus.
*Chang and Eng Bunker
Chang Bunker (จัน บังเกอร์) and Eng Bunker (อิน บังเกอร์) (May 11, 1811 – January 17, 1874) were Siamese (Thai)-American conjoined twins, conjoined twin brothers whose fame propelled the expression " ...
(1811–1874). The Bunker twins were born of Chinese origin in Siam (now Thailand), and the expression ''Siamese twins'' is derived from their case. They were joined by the areas around their xiphoid cartilages, but over time, the connective tissue stretched.
*In 1834, a set of conjoined triplets were born in Catania
Catania (, , , Sicilian and ) is the second-largest municipality on Sicily, after Palermo, both by area and by population. Despite being the second city of the island, Catania is the center of the most densely populated Sicilian conurbation, wh ...
. Two of the heads shared a neck while the other head had its own. The infant, a male, was described by Galvagni.
* Millie and Christine McCoy (July 11, 1851 – October 8, 1912), (oblique pygopagus). The McCoy twins were born into slavery in Columbus County, North Carolina, United States. They went by the stage names "The Two-Headed Nightingale" and "The Eighth Wonder of the World" and had an extensive career before retiring to the farm on which they were born.
* Giacomo and Giovanni Battista Tocci (1875? — 1912?), ( dicephalus tetrabrachius dipus)
*Josefa and Rosa Blazek (January 20, 1878 — March 30, 1922), pygopagus. The Blazek twins were born in Skrejšov, Bohemia (now the Czech Republic). They began performing in public exhibitions at the age of 13, and their act later included Rosa's son Franz. The sisters died in Chicago, Illinois.
Born 20th century
* Daisy and Violet Hilton of Brighton
Brighton ( ) is a seaside resort in the city status in the United Kingdom, city of Brighton and Hove, East Sussex, England, south of London.
Archaeological evidence of settlement in the area dates back to the Bronze Age Britain, Bronze Age, R ...
, England (1908–1969), pygopagus. The Hilton twins were performers who played musical instruments, sang, and danced. At the height of their career, they had the highest paid act in vaudeville. They also appeared in the movies '' Freaks'' and '' Chained for Life''.
* Lucio and Simplicio Godina of Samar, Philippines (1908–1936)
* Masha and Dasha Krivoshlyapova of Moscow, Russia (1950–2003), the rarest form of conjoined twins, one of few cases of dicephalus tetrabrachius tripus (two heads, four arms, three legs)
* Ronnie and Donnie Galyon of Ohio
Ohio ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Erie to the north, Pennsylvania to the east, West Virginia to the southeast, Kentucky to the southwest, Indiana to the ...
(1951–2020), omphalopagus; longest-lived conjoined twins in the world at 68 years and 250 days.
*Tjitske and Folkje de Vries of Mûnein, Netherlands (b. 1953), successfully separated in 1954
*Wariboko and Tamunotonye Davies, born July 25, 1953, in Kano, Nigeria. Separated in London by a team led by Ian Aird. Tamunotonye died postoperatively. Wariboko became a nurse.
* Lori and George Schappell of Reading, Pennsylvania
Reading ( ; ) is a city in Berks County, Pennsylvania, United States, and its county seat. The city had a population of 95,112 at the 2020 United States census, 2020 census and is the List of municipalities in Pennsylvania, fourth-most populous ...
(1961–2024), American entertainers, craniopagus. At the time of their death, they were the world's oldest living conjoined twins. ''Guinness World Records
''Guinness World Records'', known from its inception in 1955 until 1999 as ''The Guinness Book of Records'' and in previous United States editions as ''The Guinness Book of World Records'', is a British reference book published annually, list ...
'' noted that George's gender transition
Gender transition is the process of affirming and expressing one's internal sense of gender, rather than the sex assigned to them at birth. It is a recommended course of treatment for individuals experiencing gender dysphoria, providing impro ...
made him and Lori the first same-sex conjoined twins to identify as different genders.
* Ganga and Jamuna Mondal of India, born 1969 or 1970, known professionally as The Spider Girls and The Spider Sisters. Ischiopagus.
*Anna and Barbara Rozycki (born 1970), the first conjoined twins successfully separated in the UK.
*Elisa and Lisa Hansen, Ogden, Utah (1977). Born by Caesarean section on October 18, 1977, were conjoined at the top of their head (craniopagus). They were separated 1979 after 16-hour surgery, were first to both survive surgery. Elisa lost the use of her right side after the surgery, but went on to complete school, win medals in the Special Olympics, work, and act in the theatre. Elisa and Lisa died in 2020 (age 42).
* Ladan and Laleh Bijani of Shiraz
Shiraz (; ) is the List of largest cities of Iran, fifth-most-populous city of Iran and the capital of Fars province, which has been historically known as Pars (Sasanian province), Pars () and Persis. As of the 2016 national census, the popu ...
, Iran (1974–2003); died during separation surgery in Singapore. Craniopagus.
* Chang Chung-jen and Chung-i, born on December 23, 1976 in Taiwan
Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...
, and separated in 1979. Both babies survived. It was the first successful separation in Taiwan, and the fourth in the world. Chang Chung-jen died in 2019 and Chang Chung-i is still alive.
* Baby Girl A and Baby Girl B (born 1977 in New Jersey
New Jersey is a U.S. state, state located in both the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. Located at the geographic hub of the urban area, heavily urbanized Northeas ...
) shared a single six-chambered heart. Separation surgery would result in the certain death of Baby Girl A, while offering a remote chance of survival for Baby Girl B. The difficult ethical and religious concerns generated significant local newspaper coverage, as without the surgery, both twins faced certain death. C. Everett Koop
Charles Everett Koop (October 14, 1916 – February 25, 2013) was an American pediatric surgeon and public health administrator who served as the 13th surgeon general of the United States under President Ronald Reagan from 1982 to 1989. According ...
, who had already performed two successful separation surgeries in the past, held lengthy discussions with the family and their team of rabbinical advisors. At the family's request, and after obtaining a court order protecting him from any possible criminal liability, Koop agreed to lead the surgery; Koop did not seek civil indemnification for himself beforehand. Baby Girl B survived for three months, before infections led to liver failure, resulting in her death.
* Viet and Duc Nguyen, born on February 25, 1981, in Kon Tum Province, Vietnam, and separated in 1988 in Ho Chi Minh City
Ho Chi Minh City (HCMC) ('','' TP.HCM; ), commonly known as Saigon (; ), is the most populous city in Vietnam with a population of around 14 million in 2025.
The city's geography is defined by rivers and canals, of which the largest is Saigo ...
. Viet died on October 6, 2007. Ischiopagus.
*Maria and Consolata Mwakikuti of Tanzania (1996–2018); conjoined by the abdomen; died of respiratory problems resulting from an abnormal, inoperable chest deformity.
*Patrick and Benjamin Binder
Patrick and Benjamin Binder (born 2 February 1987) were conjoined twins, joined at the head, born in Germany in February 1987, and separated at Johns Hopkins Children's Center on 6 September 1987. They were the first twins to be successfully se ...
, separated in 1987 by team of doctors led by Ben Carson
Ben Solomon Carson Sr. (born September 18, 1951) is an American retired neurosurgery, neurosurgeon, academic, author, and government official who served as the 17th United States secretary of housing and urban development from 2017 to 2021. A pio ...
. Craniopagus.
*Andrew and Alex Olson, born in 1987, separated in April 1988 at the University of Nebraska Medical Center
The University of Nebraska Medical Center (UNMC) is a Public university, public Academic health science centre, academic health science center in Omaha, Nebraska. Founded in 1869 and chartered as a private medical college in 1881, UNMC became p ...
. Omphalopagus. Alex died in 2018.
* Katie and Eilish Holton, born August 1988 in Ireland, separated at age 3 and a half. Katie died 4 days after the separation surgery due to a weak heart which went into cardiac arrest.
* Abigail and Brittany Hensel are dicephalic parapagus twins born on March 7, 1990, in Carver County, Minnesota
Minnesota ( ) is a U.S. state, state in the Upper Midwestern region of the United States. It is bordered by the Canadian provinces of Manitoba and Ontario to the north and east and by the U.S. states of Wisconsin to the east, Iowa to the so ...
. Both graduated in 2012 from Bethel University, St. Paul, hired as teachers.
*Ashley and Ashil Fokeer, born on November 2, 1992, in Mauritius
Mauritius, officially the Republic of Mauritius, is an island country in the Indian Ocean, about off the southeastern coast of East Africa, east of Madagascar. It includes the main island (also called Mauritius), as well as Rodrigues, Ag ...
* Joseph and Luka Banda (born January 23, 1997, in Zambia
Zambia, officially the Republic of Zambia, is a landlocked country at the crossroads of Central Africa, Central, Southern Africa, Southern and East Africa. It is typically referred to being in South-Central Africa or Southern Africa. It is bor ...
), separated in 1997 in South Africa by Ben Carson
Ben Solomon Carson Sr. (born September 18, 1951) is an American retired neurosurgery, neurosurgeon, academic, author, and government official who served as the 17th United States secretary of housing and urban development from 2017 to 2021. A pio ...
(with a later intervention in 2001 to artificially close their skulls). Craniopagus.
*José Armando and José Luis Cevallos Herrera were born in September 1999 in Milagro, Ecuador. They were accepted in 2021 to the State University of Milagro.
*Maria del Carmen Andrade Solis and Maria Guadalupe Andrade Solis (better known as Carmen and Lupita) were born in June 2000 in Veracruz
Veracruz, formally Veracruz de Ignacio de la Llave, officially the Free and Sovereign State of Veracruz de Ignacio de la Llave, is one of the 31 states which, along with Mexico City, comprise the 32 Political divisions of Mexico, Federal Entit ...
, Mexico. They later moved to the United States for healthcare with their parents.
Born 21st century
*Maria de Jesus (Josie) and Maria Teresa Alvarez (Teresita), born joined at the skull as craniopagus twins in Guatemala
Guatemala, officially the Republic of Guatemala, is a country in Central America. It is bordered to the north and west by Mexico, to the northeast by Belize, to the east by Honduras, and to the southeast by El Salvador. It is hydrologically b ...
in 2001, were brought to UCLA Medical Center by Medical Kids International in 2002 and successfully separated.
* Carl and Clarence Aguirre, born with vertical craniopagus in Silay City, Negros Occidental
Negros Occidental (; ), officially the Province of Negros Occidental (; ), is a Provinces of the Philippines, province in the Philippines located in the Negros, Negros Island. Its capital is the city of Bacolod, of which it is geographically s ...
, on April 21, 2002. They were successfully separated on August 4, 2004.
*Tabea and Lea Block, from Lemgo, Germany, were born as craniopagus twins joined on the tops of their heads on August 9, 2003. The girls shared some major veins, but their brains were separate. They were separated on September 16, 2004, although Tabea died about ninety minutes later.
*Sohna and Mohna from Amritsar
Amritsar, also known as Ambarsar, is the second-List of cities in Punjab, India by population, largest city in the India, Indian state of Punjab, India, Punjab, after Ludhiana. Located in the Majha region, it is a major cultural, transportatio ...
, India. Born in New Delhi on June 14, 2003. They have two hearts, arms, kidneys and spinal cords while share liver, gall bladder and legs.
*Anastasia and Tatiana Dogaru, born outside Rome, Italy, on January 13, 2004. As craniopagus twins, the top of Tatiana's head is attached to the back of Anastasia's head.
* Lakshmi Tatma (born 2005) was an ischiopagus conjoined twin born in Araria district in the state of Bihar
Bihar ( ) is a states and union territories of India, state in Eastern India. It is the list of states and union territories of India by population, second largest state by population, the List of states and union territories of India by are ...
, India. She had four arms and four legs, resulting from a joining at the pelvis with a headless undeveloped parasitic twin.
* In 2005 a set of conjoined triplets was detected, characterized as tricephalus, tetrabrachius, and tetrapus parapagothoracopagus, and the pregnancy interrupted at 22 weeks.
* Kendra and Maliyah Herrin, ischiopagus twins separated in 2006 at age 4
*Krista and Tatiana Hogan
Krista and Tatiana Hogan (born October 25, 2006) are two Canadian conjoined craniopagus twins. They are joined at the head and have separate brains that are interconnected by a thalamic bridge within a shared skull. They were born in Vancouver, ...
, Canadian
Canadians () are people identified with the country of Canada. This connection may be residential, legal, historical or cultural. For most Canadians, many (or all) of these connections exist and are collectively the source of their being ''C ...
twins conjoined at the head. Born October 25, 2006. Share part of their brain and can pass sensory information and thoughts between each other.
* Trishna and Krishna from Bangladesh were born in December 2006. They are craniopagus twins, joined on the tops of their skulls and sharing a small amount of brain tissue. In 2009, they were separated in Melbourne, Australia.
* Maria and Teresa Tapia, born in the Dominican Republic on April 8, 2010. Conjoined by the liver, pancreas, and a small portion of their small intestine. Separation occurred on November 7, 2011, at Children's Hospital of Richmond at VCU.
*Zheng Hanwei and Zheng Hanjing, born in China on August 11, 2013. Conjoined by their sternum, pericardium, and liver. In 2014, they were separated in Shanghai, China, at the Shanghai Children's Medical Center.
*Jadon and Anias McDonald, born in September 2015. Conjoined by the head. Successfully separated at Children's Hospital of Montefiore Medical Center by James T. Goodrich in October 2016.
*Erin and Abby Delaney, born in Philadelphia, Pennsylvania, on July 24, 2016. Conjoined by the head. They were successfully separated at Children's Hospital of Philadelphia
The Children's Hospital of Philadelphia, also known by its acronym CHOP, is a children's hospital in Philadelphia, Pennsylvania. Its primary campus is located in the University City, Philadelphia, University City neighborhood of West Philadelph ...
on June 16, 2017.
*Marieme and Ndeye Ndiaye, twin girls born in Senegal in 2017, living in Cardiff, UK in 2019.
*Callie and Carter Torres, born January 30, 2017, in Houston Texas, from Blackfoot Idaho. They are omphalo-ischiopagus conjoined twins, attached by their pelvic area and sharing all organs from the belly button down with just one leg each.
*Yiğit and Derman Evrensel, twin boys born on June 21, 2018, Antalya, Turkey. They are craniopagus twins and were separated at Great Ormond Street Hospital in 2019 by the same surgeons that separated Safa and Marwa Bibi.
*Ervina and Prefina, born June 29, 2018, in the Central African Republic
The Central African Republic (CAR) is a landlocked country in Central Africa. It is bordered by Chad to Central African Republic–Chad border, the north, Sudan to Central African Republic–Sudan border, the northeast, South Sudan to Central ...
. They were separated on June 5, 2020, at the Bambino Gesù Pediatric Hospital in Rome, Italy.
*Mercy and Goodness Ede, born August 13, 2019, conjoined by the chest and abdomen. Successfully separated at the National Hospital in Abuja, Nigeria in November 2019.
*Marie-Cléa and Marie-Cléanne Papillon, born in Mauritius in 2019. Conjoined from neck to abdomen, but also at the heart which had seven chambers, instead of four. Marie-Cléa did not survive the surgery to separate the two.
*Valentina and Kristina, born in 2019 in Croatia, shared a part of the digestive system and liver (xypho-omphalopagus). Several months after birth they developed twin-to-twin transfusion syndrome due to blood shunting, and they were successfully separated at University Hospital Centre Zagreb (Rebro) in an urgent procedure.
*Sheneeva and Chenelva Kolestein, born in Surinam in 2021 and living in the Netherlands in 2025.
*Susannah and Elizabeth Castle, born April 22, 2021, and separated December 10, 2021, in Philadelphia, Pennsylvania.
*AmieLynn Rose and JamieLynn Rae Finley, born October 3, 2022, and separated January 23, 2023, in Fort Worth, Texas.
In fiction
Conjoined twins have been the focus of several works of fiction, including:
* Robert A. Heinlein's '' Orphans of the Sky'' features Joe-Jim Gregory, the two-headed leader of a powerful mutie gang, who understands the Ship's nature better than anyone else onboard.
* Lori Lansens's second novel '' The Girls'' (2005) is the life story of craniopagus twin sisters.
* Irish author Sarah Crossan's verse novel ''One'' follows the life and survival of conjoined twin sisters. It won the Carnegie Medal, ''The Bookseller
''The Bookseller'' is a British magazine reporting news on the publishing industry. Philip Jones is editor-in-chief of the weekly print edition of the magazine and the website. The magazine is home to the ''Bookseller''/Diagram Prize for Oddes ...
'' 2016 prize for young adult fiction, and the Irish Children's Book of the Year.
* Lidija Dimkovska's ''A Spare Life'' (Резервен живот), 2012, translated into English by Christina E. Kramer, Two Lines Press, San Francisco, USA, 2016, tells of two conjoined sisters growing up in Macedonia just before the breakup of Yugoslavia.
See also
* Medical law
* Monoamniotic twins
* Polycephaly
Polycephaly is the condition of having more than one head. The term is derived from the Greek stems ''poly'' (Greek: "πολύ") meaning "many" and ''kephalē'' (Greek: "κεφαλή") meaning "head". A polycephalic organism may be thought ...
Notes
References
External links
Types and social history of conjoined twins
The site of the medical Saudi team responsible for numerous successful separation surgeries
* ttp://www.thehumanmarvels.com/ The Human Marvels: A Historical Reference Site run by J. Tithonus Pednaud, Teratological Historian
Cases of conjoined and incomplete twins
Clara and Alta Rodriguez
joined at the pelvis and successfully separated in 1974 at Children's Hospital of Philadelphia by surgeons including C. Everett Koop
Charles Everett Koop (October 14, 1916 – February 25, 2013) was an American pediatric surgeon and public health administrator who served as the 13th surgeon general of the United States under President Ronald Reagan from 1982 to 1989. According ...
National Library of Medicine: Selected Moments in the History of Conjoined Twins
Conjoined Twins Fast Facts
(also lists additional twins)
(this article includes post-mortem images)
The St. Benoit Twins
, ''Scientific American
''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it, with more than 150 Nobel Pri ...
'', July 13, 1878, p. 24
{{DEFAULTSORT:Conjoined Twins
Rare diseases