Arun Prasad, Kanchan Kapoor, Anshu Sharma, Joseph Abraham. Conjoined Twins (Thoraco – omphalopagus), Int J Intg Med Sci (2015), 2 (10): 170-174.

Abstract

Conjoined twins are a rarely seen congenital anomaly with severe mortality. Among the different variety of conjoined twins, Thoraco-omphalopagus is the most common type, wherein the two foetuses are joined at thorax and upper abdomen region. In this type of twins usually there is single heart, but lungs will be separate. In GIT, the foregut will be separate, but midgut may be shared by both twins. Hindgut will be separate. The exact cause is unknown, but it is mostly considered to be an irregular division of the zygote. One such case was observed during routine foetal autopsy performed in Dept of Anatomy, GMCH-32, and Chandigarh. The mother was 21yrs old prime gravida and the condition was diagnosed at the time of USG examination at 13+6 weeks of gestational age. Autopsy was performed after taking full consent. The foetuses had single umbilical cord and sex of both the foetuses was male. After autopsy it was found that both foetuses shared single heart, stomach, small intestine, large intestine, liver and spleen. However there was development of separate lungs and organs of Genito-urinary system. There are two theory proposed for the formation of the conjoined twins. A fusion theory which is more accepted and other one is fission theory. The exact mechanism of formation of twins, obstetrical and surgical importance and other details will be discussed in detail with the available literature.

Full text

Int J Intg Med Sci 2015;2(10):170-74. ISSN 2394 - 4137 170
Case Report
Conjoined Twins (Thoraco-Omphalopagus)
Prasad Arun *1, Kapoor Kanchan 2, Sharma Anshu 3, Abraham Joseph 4.
*1 Department of Anatomy, Andaman Nicobar Islands Institute of Medical Sciences, Port Blair,
India.
2,3,4 Department of Anatomy, Government Medical College, Chandigarh, India.
Conjoined twins are a rarely seen congenital anomaly with severe mortality. Among the different variety of
conjoined twins, Thoraco-omphalopagus is the most common type, wherein the two foetuses are joined at
thorax and upper abdomen region. In this type of twins usually there is single heart, but lungs will be separate.
In GIT, the foregut will be separate, but midgut may be shared by both twins. Hindgut will be separate. The exact
cause is unknown, but it is mostly considered to be an irregular division of the zygote. One such case was
observed during routine foetal autopsy performed in Dept of Anatomy, GMCH-32, and Chandigarh. The mother
was 21yrs old prime gravida and the condition was diagnosed at the time of USG examination at 13+6 weeks of
gestational age. Autopsy was performed after taking full consent. The foetuses had single umbilical cord and
sex of both the foetuses was male. After autopsy it was found that both foetuses shared single heart, stomach,
small intestine, large intestine, liver and spleen. However there was development of separate lungs and organs
of Genito-urinary system. There are two theory proposed for the formation of the conjoined twins. A fusion
theory which is more accepted and other one is fission theory. The exact mechanism of formation of twins,
obstetrical and surgical importance and other details will be discussed in detail with the available literature.
KEY WORDS: Conjoined Twins, Thoraco-ompahlopagus, Congenital Anomaly.
Online Access and Article Informtaion
International Journal of Integrative Medical Sciences
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ABSTRACT
INTRODUCTION
Address for correspondence: Dr. Arun Prasad, Department of Anatomy, Andaman Nicobar Island
Institute of Medical Sciences, Port Blair, Andaman Nicobar Islands, India.
E-Mail: drprasadarun@gmail.com
International Journal of Integrative Medical Sciences,
Int J Intg Med Sci 2015, Vol 2(10):170-74. ISSN 2394 - 4137
DOI: http://dx.doi.org/10.16965/ijims.2015.130
Quick Response code
Received: 12-10-2015
Reviewed: 12-10-2015 Accepted: 02-11-2015
Published: 10-11-2015
Source of Funding: Self Conflicts of interest: None
DOI: 10.16965/ijims.2015.130
Babies come into the world heralding the good
news that the human species with all its diversit-
ies and complexities is still going good. Though
a new-born brings in its wake untold happiness
to those around, there are some unfortunate
babies whose birth is clouded with sadness and
worry for the parents because of the birth
defects [1] in them that are manifest either
immediately defects like cleft lip, cleft palate,
Down syndrome, autism, muscular dystrophy,
neural tube defects, congenital heart disorders
to rare birth defects such as cleft foot and hand,
club foot, aglossia and albinism, to name a few
after birth or after a while, depending on the
nature of the congenital abnormality. Birth
defects include abnormalities in the new born
baby’s (structure, function or body metabolism),
which usually lead to physical and mental
disabilities and can even be fatal sometimes.
There are many causes for birth defects involving
a wide range of factors some due to hereditary
abnormality, some caused by chromosomal
disorders or genetic disorder and some others
caused by environmental agents.
All over the world as per the 2015 studies
Congenital anomalies affect approximately 1 in
33 infants leading to 6.6% deaths in infants and

Int J Intg Med Sci 2015;2(10):170-74. ISSN 2394 - 4137 171
causing significant morbidity in children. Birth
defects are present in about 3% of new-borns
[2]. Congenital anomalies resulted in about
632,000 deaths per year in 2013 down from
751,000 in 1990 [3-6]. The type with the greatest
death are congenital heart disease (323,000),
followed by neural tube defects (69,000) [7].
Many studies have found that the frequency of
occurrence of certain congenital malformations
depends on the sex of the child [4-8]. Now
various techniques are available to detect
congenital anomalies in fetus before birth. About
3% of new-borns have a “major physical
anomaly”, meaning a physical anomaly that has
cosmetic or functional significance [9]. Physical
congenital abnormalities are the leading cause
of infant mortality in the United States,
accounting for more than 20% of all infant
deaths. Seven to ten present of all children will
require extensive medical care to diagnose or
treat a birth defect [10]. Among new-borns is
between 2-3% that is similar to that found in
the industrialized world (ICBDMS, 1991)
Congenital anomalies account3 for 8-15% of
perinatal deaths and 13-16% of neonatal deaths
in India.
Conjoined twins are rarely seen congenital
anomaly with severe mortality occurring in
1:50,000 - 1:60,000 live births. Among the
different variety of conjoined twins, Thoraco-
ompholopagus is the most common type,
wherein the two foetuses are joined at thorax
and upper abdomen region. Teratologists have
proved that congenital abnormalities in animals
can be induced but no one has been able to
prevent the occasional occurrence of conjoined
twins. Untill this is achieved; surgeons will be
concerned with repair procedures, primarily
depending upon the morphology of the
abnormality. The opportunity to dissect
ischiopagus, whose incidence among conjoined
twins is very low (6%) is worth reporting [11].
Case Report
The different variety of conjoined twins Thoraco-
ompholopagus is the most common type,
wherein the two foetuses are joined in the thorax
and upper abdomen region. In this type of twins
usually they will share a single heart, but lungs
will be separate. The GIT system the foregut part
will be separate, but midgut may be shared by
both twins. Hindgut will be separate. The exact
cause is unknown, but it is mostly considered to
be irregular division of the zygote. Here we are
reporting a case of Thoraco-ompholopagus.
During a routine foetal autopsy, a foetus was
found to have a thoracophagus in the Dept. of
anatomy, GMCH-32, Chandigarh. The mother
was 21yrs old primi-gravida and the condition
was diagnosed at the time of USG examination
at 13+6 weeks of gestational age. A primigravid
was diagnosed thru USG as Thoracophagus and
pregnancy was terminated and abortus was sent
to our department for autopsy. Antenatal history
was normal with routine check-ups and intake
of vit-B12 and folic acid tablets. Medical and
past history was not significant. No significant
family history. Autopsy was performed after
taking full consent.
OBSERVATIONS
External examination:
· Both were male foetus.
· Foetuses were fused at thorax and upper
abdomen region.
· Both foetuses had separate urogenital
openings.
· Both foetuses had imperforate anus.
· Limbs were separate.
· Left side foetus showed amniotic bands at
midthigh level on left side.
· They had single umbilical cord.
Internal Examination:
· Incision was given to open the fused region.
· The thoracic and abdominal cavities were
opened.
· Following observations were seen.
· Single heart.
· Trachea fused in the middle region. In upper
and lower part they were separate to both
foetuses. They both had separate lungs.
· In GIT: both foetuses had separate oesophagus
which opened into common stomach. Small
intestine and large intestine were shared inside
both foetuses. Sigmoid colon was seen on right
side only.
· Liver was present on right foetus and spleen
in left foetus.
Pra sad Arun, Kapoor Kanch an, Sharma Anshu, Abraham Joseph . Conjoined Twins (Thoraco-Omph alopag us): A Case Report.

Int J Intg Med Sci 2015;2(10):170-74. ISSN 2394 - 4137 172
Pra sad Arun, Kapoor Kanch an, Sharma Anshu, Abraham Joseph . Conjoined Twins (Thoraco-Omph alopag us): A Case Report.
· In Gentio-Urinary system: Both foetuses had
their own gentio-urinary system.
Fig. 1: Showing the Internal Examination of the
Conjoined Twins (Thoraco-Omphalopagus).
Fig. 2: Showing the External Examination of the Conjoined
Twins (Thoraco-Omphalopagus).
Fig. 3: X-Ray showing
the External Examina-
tion of the Conjoined
Twins (Thoraco-
Omphalopagus).
DISCUSSION
Conjoined twinning was first described in
1100AD. The first case diagnosed by USG was
reported in 1977. It is rare abnormality estimated
to occur in about 1% of monozygotic twins.
Depending upon the site of fusion it is divided
into different types of conjoined twins. Robertson
in 1953 studied conjoined twins and determined
the incidence of various types as being 73%
thoracophagus, 19% Pygopagus, 6% ischiopagus
and 2% craniopagus. The female conjoined twins
are two to three times more common than male
twins. Higher incidence of anomalies in still
births [12] and the incidence of congenital
anomalies were significantly higher in preterm
babies [13], low birth weight infants [14],
mother’s age above 35 years [15], increased
maternal age [16], and increased birth order. The
factors that significantly increase the risk of
congenital malformations to be presence of
hydramnios, maternal febrile illness in the first
trimester, past history of abortions, diabetic
mother, eclampsia, previous abortion and history
of congenital heart disease in previous child or
malformed babies. Mother having diabetes
mellitus, arterial hypertension, and
hypothyroidism shows a positive association
[17] with congenital malformations. The annual
report of Indian Council of Medical Research [18]
says that the commonest congenital
malformations are cardiac in nature.
Cardiovascular, musculoskeletal and genito-
urinary were the most commonly affected
systems in a descending order of frequency.
With special reference to the neural tube defect
(NTD) [19], the incidence of NTD has markedly
reduced in the developed countries following
mass promotion and mandatory prescription of
folic acid for pregnant mothers. The incidence
of congenital heart disease was the leading
congenital malformation followed by
musculoskeletal system.
Types of Conjoined Twins:
Inferior Conjuncti on Lower body is si ngle or twins joi ned by s ome l ower porti on of body
Diprosopus Two faces with one head a nd body
Dicephal us Two heads with one body
Ischi opagus Joined by inferior s acrum and coccyx
Pygopagus Joined by posterolateral s acrum and coccyx
Superior Conjunction Upper body is s ingle or twins joined by s ome upper body portion
Dipygus Single head, thorax, abdomen with two pelves and four l egs
Syncepha lus Facia l fusion with or without thoraci c fusi on
Craniopagus Joined at the head
Middle Conjunction Fusion of the midportion of the body, separate above and below
Thorac opagus Thorac ic fus ion
Omphalopagus
(Xiphopagus) Joined from umbi licus to xiphoi d carti lage
Thorac o-omphalopagus Thoracic and a bdominal fusi on
Rachipagus Vertebral fus ion above the sacrum

Int J Intg Med Sci 2015;2(10):170-74. ISSN 2394 - 4137 173
The exact aetiology for the occurrence of twins
is unclear. But two theories have been proposed
to explain this phenomenon. The traditional
theory is fission theory, in which the fertilized
egg splits partially and conjoined twins represent
delayed separation of the embryonic mass after
day 12 of fertilization. The second theory is
fusion, in which a fertilized egg completely
separates, but stem cells (which search for
similar cells) find like stem cells on the other
twin and fuse the twins together. Generally this
type of cases normal delivery is not possible if
the fetuses survive up to term.
Prenatal ultrasonography leads to early detection
of malformations and facilitates early surgical
intervention. Ultrasound at around 20 - 21 weeks
has long been considered for screening
pregnancies for structural malformations. Use
of second trimester ultrasound for detection of
chromosomal anomalies was first suggested in
1985 [20]. Chromosomal defects were
progressively found to be associated with certain
sonographic features, including biometric
parameters (e.g., short length of femur and
humerus, pyelectasis, large nuchal fold,
ventriculomegaly, early fetal growth restriction)
and morphologic signs (e.g., choroids plexus
cysts, echogenic bowel, echogenic intracardiac
focus). Data on the validity of those markers as
predictors of chromosomal anomalies (mostly
related to Down syndrome) are at variance
depending upon the author [22]. There may be
multi factorial reasons for these namely lack of
awareness among people to get level 3
ultrasound during antenatal period, poverty, lack
of proper health services in periphery. The main
purpose of the study is we need to involve and
make aware all the health care workers who are
providing maternal and child health care working
in government or private sector so as to quantify
exact prevalence rate of congenital
malformations involving any particular system.
Mortality and morbidity can be because of
sepsis, infections, prematurity or delay in
treatment due to late admissions after diagnosis
due lack of money, poor background and lack of
awareness. This study definitely helps to know
the pattern of congenital anomalies and their
outcome in this area so that strategies for
prevention, early detection and timely manage-
ment can be sort out.
Management: Prenatal diagnosis by USG should
be done. Surgery to separate conjoined twins
may vary from relatively simple to extremely
complex, depending on point of attachment and
the internal organs that are shared, but it is life
threatening.
CONCLUSION
The prognosis of this type of twins is generally
poor. Once conjoined twins have been diagno-
sed, characterization of the type and severity of
the abnormality should be assed using three-
dimensional USG or MRI. Termination of
pregnancy should be suggested to the family.
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Int J Intg Med Sci 2015;2(10):170-74. ISSN 2394 - 4137 174
Pra sad Arun, Kapoor Kanch an, Sharma Anshu, Abraham Joseph . Conjoined Twins (Thoraco-Omph alopag us): A Case Report.
How to cite this article:
Prasad Arun, Kapoor Kanchan, Sharma Anshu, Abraham Joseph. Conjoined
Twins (Thoraco-Omphalopagus): A Case Report. Int J Intg Med Sci
2015;2(10):170-174. DOI: 10.16965/ijims.2015.130
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