Conjoined twins occur in approximately 0.2:10,000 births; the obstetrician and sonographer only rarely examine them. In Western countries, discovery of conjoined twins is often made by the end of the first trimester; however, in the third world, conjoined twins are often discovered only at birth.
To evaluate how ultrasound techniques, when possibly available, may improve management and counseling when conjoined twins are confirmed.
Material and Methods
The authors report two different cases of union of two equal twins with sole umbilical cord.
The two cases presented with non contributive medical history and no prior teratogen exposure and an unfavorable prognosis.
Early discovery of viable conjoined twins permits assessment of the best route of delivery and a planning for serial sonography and fast MRI to plan eventual separation surgery or fetus after-birth surviving possibilities.
conjoined twins; ultrasound
To assess the findings in conjoined twins diagnosed prenatally.
Material and Methods
Between January 2002 and June 2009, we reviewed the database and medical records of 857 twin pregnancies, including 140 monochorionic twins. Nineteen monochorionic-monoamniotic twin pregnancies were detected, four of which were complicated by conjoined twins.
Of these 4 cases, 2 were complicated by thoracopagus and one had thoraco-omphalopagus; these three cases underwent termination at 16, 11, and 19 weeks gestation, respectively. The last case was diagnosed as a pygopagus tetrapus parasitic twin at 28 weeks gestation. The family decided to continue the pregnancy, and achieved a successful outcome with elective surgery postpartum.
Conjoined twins are an uncommon and complex complication of monozygotic gestations, which is associated with high perinatal mortality. The early prenatal diagnosis of conjoined twins allows improved counseling about the management options, including maintenance of pregnancy with surgery after delivery or termination of pregnancy.
Conjoined twins; prenatal diagnosis
This study reports on the experience of one hospital regarding the surgical aspects, anatomic investigation and outcomes of the management of 21 conjoined twin pairs over the past 20 years.
All cases of conjoined twins who were treated during this period were reviewed. A careful imaging evaluation was performed to detail the abdominal anatomy (particularly the liver), inferior vena cava, spleen and pancreas, either to identify the number of organs or to evaluate the degree of organ sharing.
There were eight sets of ischiopagus twins, seven sets of thoracopagus twins, three sets of omphalopagus twins, two sets of thoraco-omphalo-ischiopagus twins and one set of craniopagus twins. Nine pairs of conjoined twins could not be separated due to the complexity of the organs (mainly the liver and heart) that were shared by both twins; these pairs included one set of ischiopagus twins, six sets of thoracopagus twins and one set of thoraco-omphalo-ischiopagus twins. Twelve sets were separated, including seven sets of ischiopagus twins, three sets of omphalopagus twins, one set of thoracopagus twins and one set of craniopagus conjoined twins. The abdominal wall was closed in the majority of patients with the use of mesh instead of the earlier method of using tissue expanders. The surgical survival rate was 66.7%, and one pair of twins who did not undergo separation is currently alive.
A detailed anatomic study of the twins and surgical planning must precede separation. A well-prepared pediatric surgery team is sufficient to surgically manage conjoined twins.
Conjoined Twins; Surgical Separation; Ischiopagus Tripus Conjoined Twins; Omphalopagus Conjoined Twins; Thoracopagus Conjoined Twins
Objective: To summarize our experience in the anesthetic management of conjoined twins undergoing one-stage surgical separation.
Methodology: Medical records of conjoined twins admitted to our hospital for treatment and considered for surgical separation from 1996 to present were retrospectively reviewed. Four cases of conjoined twins underwent one-stage surgical separation under general anesthesia. Preoperative evaluation was performed to determine the extent of anatomical conjunction and associated anomalies. Anesthesia was simultaneously induced in all conjoined twins. The intubation procedure was successfully performed with the head slightly rotated to each baby’s side, followed by the administration of vecuronium. Anesthetic agents were administered according to the estimated weight of each baby. One case of conjoined twins underwent surgical separation with cardiopulmonary bypass due to shared hearts.
Results: All conjoined twins were successfully separated. No significant respiratory or cardiac events occurred during surgery except for one twin, which died after separation because of complicated congenital heart disease.
: Accurate preoperative evaluation, respiratory and circulatory management, and close cooperation of the multidisciplinary team are important aspects of anesthetic management of conjoined twins surgery.
Conjoined twins; Separation; Anesthetic management; Surgery
Two pairs of omphalopagus twins were encountered at the Polish Mother's Health Institution in Lodz, Poland during the past 15 years. In the first set the prenatal diagnosis was not established and the delivery of the twins in a regional hospital was a complete surprise. Both babies died. In the second case the conjoined twins were diagnosed prenatally, surgical separation was successful, and both twins survived. The prenatal identification of conjoined twins is of cardinal importance for the planning of delivery and possible separation.
conjoined twins; prenatal diagnosis; surgical separation
This paper is written in response to controversial judicial decisions following separation surgery on conjoined twins "Jodie" and "Mary". The courts, it is argued, seem to have conceptualised the twins as "entangled singletons" requiring medical intervention to render them physically separate and thus "as they were meant to be", notwithstanding the death of the weaker twin, "Mary". In contrast, we argue that certain notions, philosophical and biological, of what human beings are intended to be, are problematic. We consider three compelling conceptualisations of conjoined twins and advocate a model that conceives them as two psychologically separate individuals who happen to share a body, the sharing of a body being integral to the individuality of each twin. While we reject an "essentialist" view of the conjoined state, a view which might render separation surgery unthinkable in all cases, we nevertheless argue against an "adversarial" interpretation of conjoined twins' respective best interests. We maintain that the physical entanglement should be regarded as a shared problem rather than one posed by one twin to the other. And if, after deliberation, separation surgery is deemed the "least detrimental alternative" or the "lesser of two evils", then there should be recognition of what conjoined twins will lose, as well as gain, through separation. The current drive to separate twins at all costs may evince a deeper unease with bodily configurations that appear to threaten the premium that the Western ethical and legal tradition places on personal sovereignty, and the physical circumscription that such sovereignty assumes.
We present a case of female cephalothoracoomphalopagus conjoind twin, which is extremely rare type of conjoined twins. We also review the contemprory knowledge regarding incidence, etiopathogenesis, antenatal diagnosis and outcone or the prognosis of conjoint twins. The case belong to hindu female, no history of consanguineous marriage, ingestion of drugs or exposure to any radiation. History of one abortion and one twin delivery present. Conjoind twin was cephalothoracoomphalopagus type, delivered vaginaly at 30 wks of gestion to a 25 yrs old multigravida. Management of conjoind twin still remain challenges because of multiple congenital anomalies and poor outcome is seen.
Cephalothoracoomphalopagus; conjoind twin; outcome
Background. Conjoined twins are a rare complication of monozygotic twinning and are associated with high perinatal mortality. Case. Here we present a case of conjoined twins in a triplet pregnancy diagnosed at 13 of weeks gestation. With the aid of 3D ultrasound and MRI images, the parents were counseled regarding the management options, including continuation of pregnancy, termination of pregnancy, or selective fetocide. They chose selective fetocide of the conjoined twins and went on to deliver the remaining triplet at term. Conclusion. This case represents to our knowledge the only MRI images of conjoined twins in a triplet pregnancy and demonstrates how 3D imaging can be used to better counsel patients about management options.
Objective. Conjoined twin is a rarely seen congenital anomaly together with severe mortality and morbidity. The more common types of conjoined twins include the thoracopagus type, where the fusion is anterior, at the chest, and involves the heart. We are reporting one case of conjoined thoracopagus twins diagnosed by ultrasonography at 11 weeks. Case Report. In a multigravid pregnant woman who has been admitted to our clinic with a diagnosis of conjoined twins, thoracopagus, by ultrasonography at an 11-week gestation, termination of the pregnancy was performed. Conclusion. Making an early diagnosis with ultrasonographic examination gives the parents a chance to elect pregnancy termination.
Dicephalic parapagus tribrachius conjoined twin is a very rare condition.
We present a case of 5-days-old male dicephalic parapagus conjoined twins. The conjoined twins were diagnosed in 4th month of pregnancy by ultrasonography. The pregnancy terminates at 36 weeks by cesarean section and triplets were born. The babies were male conjoined twins and another healthy male baby. Many congenital defects of interest can now be detected before birth. Sever form of this malformation precludes postpartum life. It is supposed that with advances in screening methods for prenatal diagnosis these cases are terminated in first or second trimester of pregnancy.
Dicephalic Parapagus Tribrachius; Conjoined Twins; Triplet Pregnancy
To review the history, epidemiology, etiology, gestational aspects,
diagnosis and prognosis of imperfect twinning.
Scientific articles were searched in PubMed, SciELO and Lilacs databases,
using the descriptors "conjoined twins", "multiple
pregnancy", "ultrasound", "magnetic
resonance imaging" and "prognosis". The
research was not delimited to a specific period of time and was supplemented
with bibliographic data from books.
The description of conjoined twins is legendary. The estimated frequency is
1/45,000-200,000 births. These twins are monozygotic, monochorionic and
usually monoamniotic. They can be classified by the most prominent fusion
site, by the symmetry between the conjoined twins or by the sharing
structure. The diagnosis can be performed in the prenatal period or after
birth by different techniques, such as ultrasound, magnetic resonance
imaging and echocardiography. These tests are of paramount importance for
understanding the anatomy of both fetuses/children, as well as for prognosis
and surgical plan determination.
Although imperfect twinning is a rare condition, the prenatal diagnosis is
very important in order to evaluate the fusion site and its complexity.
Hence, the evaluation of these children should be multidisciplinary,
involving mainly obstetricians, pediatricians and pediatric surgeons.
However, some decisions may constitute real ethical dilemmas, in which
different points should be discussed and analyzed with the health team and
twins; twins, conjoined; twins, monozygotic; pregnancy, multiple; prognosis
Conjoined twins show varying degree of conjoining in either facing or side-by-side fashion. Cephalothoracopagus janiceps is a prototype of facing anomaly in which the two bodies demonstrated a cross symmetry to the midline, that is axial symmetry. Interfacial and intersternal lines crossed at a right angle and no abnormality of situs was associated. Dicephalus dipus dibrachius is a case of side-by-side union, in which the bodies facing nearly the same direction were symmetrical to the middle sagittal plane. Abnormal situs of one was always associated. Other types of conjoined twins as thoracopagus lie between the two extremes of facing and side-by-side union. The three dimensional architectures of the organs in each type would be explained using cross sectional figures of skull, thorax and pelvis. Although the facing twins share the internal organs without fusion, the organs in the side-by-side component are fused with modification of the situs. We postulate sixteen pairs of situs and four manners of division for the explanation of the midline organs and the presence of a dominant co-twin. The splenic locations in a given cardiopulmonary situs are evaluated for the appraisal and applicability of these hypotheses.
Nearly completed conjoined or fused symmetrical twins are generally called diplopagus. Sheep conjoined twins have been reported less than cow. An apparently female conjoined twin lambs was examined based on external and internal features. In radiology, two vertebral columns and two pairs of the ribs were seen. Only two heads and two necks were separated (thoraco-omphalopygopagus). There were three forelimbs (tribrachius), one of which grew on dorsal region as a notomelus. Teat buds of the monsters differed in number. Only one lamb had umbilicus, including one umbilical vein, and two umbilical arteries locating besides one urinary bladder. This lamb had also one uterus. Two-separated alimentary tracts were observed in a common abdomen. Common thorax and abdominal cavities were separated by a diaphragm. There were two esophageal hiatuses, and two caval foramina but only one aortic hiatus. Two pairs of lungs and two unequal and connected hearts in a common pericardium were observed. Abnormality of the circulatory system might have caused the death of the twins.
Conjoined twins; Diplopagus; Notomelus; Sheep; Tribrachius
It is usually held that there is a time continuum in the formation of monoxygotic (MZ) twins which is indexed by their placentation, running from dichorionic to monochorionic diamniotic to monochorionic monoamniotic and conjoined pairs. There is good evidence that this continuum is characterised by a continuum of predisposition to anencephaly, slightly raised in dichorionic pairs but very high in some sorts of conjoined pairs. Although MZ twins, especially monoamniotic and conjoined pairs, are peculiarly liable to anencephaly, they are not particularly susceptible to spina bifida. Among twin pairs concordant for anencephaly or spina bifida, there are strikingly few concordant in the sense of one twin having anencephaly and the other spina bifida, in contrast with the numbers of pairs concordant for the same malformation. The prevalence of anencephaly in double monsters varies with the type of monster, being high in diprosopus. These findings may be explained by the timing of embryonic events.
Thoracopagus twins were delivered at 37 weeks' gestation by caesarean section. Respiratory distress was present and mechanical ventilation was needed; 36 hours after delivery severe lactic acidosis developed and the twins died. The pericardial sac was common and the hearts were conjoined as a single structure with ventricular fusion.
Anaesthesia for conjoined twins, either for separation surgery, or for MRI or other evaluation procedures is an enormous challenge to the paediatric anaesthesiologist. This is an extra challenging surgery because we the anaesthesiologists need to care for two patients at the same time instead of just one. Anaesthesia for conjoined twins ‘separation surgery mainly centered on the following concerns: 1.Conjoined Twins’ physiology like crossed circulation, distribution of blood volume and organ sharing with their anaesthetic implications. 2.Long marathon surgery with massive fluid shifts and loss of blood & blood components and their rapid replenishment. 3.Meticulous planning for organized management of long hours of anaesthetic administration in two paediatric subjects simultaneously with multi surgical specialties' involvement and their unique requirements. We report the anaesthetic and intensive care management of one pair of Pygopagus separation surgery and also the review of literature and world statistics.
Conjoined twins; Separation surgery; Anaesthesia; Monitoring
Laterality defects are quite common in thoracoileopagus and parapagus dicephalus but rare in other types of conjoined twins.
To present the presumed laterality defects in cephalothoracoileopagus and prosopothoracoileopagus conjoined twins, based on the unilateral or bilateral absence or duplication of the spleen.
Materials and methods
Three human anatomical specimens of craniothoracoileopagus (CTIP) twins and one of prosopothoracoileopagus (PTIP) twins were investigated. The specimens were part of the Museum Vrolik collection of the Department of Anatomy and Embryology of the Academic Medical Centre, University of Amsterdam, The Netherlands. The specimens were taken out of their jars and scanned with multidetector CT and volumetric T2-weighted MRI at 1.5 T.
The internal anatomy of the specimens was largely in accordance with previous reports. However, there was no recognisable spleen in the right twin in one CTIP specimen, in the left twin in one other CTIP specimen, and in both twins in the third CTIP specimen and in the PTIP specimen.
Asplenia and polysplenia are considered reliable indicators of right and left isomerism, respectively. However, three of our four specimens had laterality patterns that did not correspond with those previously reported. Since no other parameters of laterality defects could be verified in these specimens, we concluded that asplenia was unlikely to be caused by laterality defects.
Conjoined twins; Laterality defects; Imaging; Historical specimen
Conjoined twins are rare and present a unique challenge to pediatric surgeons and radiologists. An imaging strategy to accurately define anatomic fusion, vascular anomalies, and other associated abnormalities is important for surgical planning and prognostic information. A conjoined female twin with a combined weight of 2.8 kg was born by emergency caeserean. Hence, a computed tomography scan of the thorax and entire abdomen at 1.25 mm slice thickness was performed to delineate the internal structures of the twins. CT-angiography defined specific vascular supply which determined the distribution of shared structures between the twins. An echocardiogram showed four heart chambers with atrioventricular septal defect. To further evaluate the heart chambers, the twin was planned for gated cardiac magnetic resonance imaging. Unfortunately, they succumbed 6 hours apart due to complication of septicemia. Magnetic resonance imaging and CT scan provide excellent anatomic detail, demonstrating organ position, shared viscera, and limited vascular anatomy, whilst angiography defined specific vascular supply, useful in determining the distribution of shared structures between the twins in planning for surgery.
A conjoined twin is one of the rare congenital defects. Ischiopagus variety is even rarer. We present a case of ischiopagus-tripus conjoined twins. They were fused at the lower halves of the bodies. One of the twins was apparently normal looking, active and pink. The other twin was small, ill looking, sluggish and cyanosed. There were two well formed separate lower limbs on one side and a fused limb at the other side. The twins had an imperforate anus and two small orifices draining urine with incompletely developed external genitalia. Pre-operative workup was in progress when the twins passed away.
Conjoined Twins; Ischiopagus; Tripus; Tetrapus
Asymmetric and parasitic conjoined twins are rarer anomalies of monochorionic monoamniotic twins, consisting of an incomplete twin attached to the fully developed body of the co-twin.
A 30-year-old multigravid woman referred to maternal fetal unit due to polyhydramnios at 28th week of gestation. Sonographic examination revealed a single fetus and polyhydramnios with amniotic fluid index 30 cm. The fetus had normal apparent single head, spine, thorax, abdomen, two upper and two lower limbs, and two relatively well developed rudimentary parasitic lower limbs at sacral region. Lower limbs of the autosite were moving freelly but no movement was detected at the parasite. The parasite contained irregular lower limbs and left foot with three toes. Short and deformed long bones were also present in the parasitic limbs. A Cesarean section was performed at 38th week of gestation and a live female infant weighing 3600 g was delivered. The parasitic lower limbs were totally excised. Post-operative period was uneventful and the newborn was discharged as healthy. Post-natal follow-up was normal at nine-month-old.
Pygopagus tetrapus parasitic twin is a rare form of conjoined twins and in utero diagnosis with ultrasound assists in prenatal management and counselling with parents.
12 cases of conjoined twins from West Africa were reported between 1936 and 1978. Eight sets were liveborn and were surgically separated either in local hospitals or abroad. Four were stillborn. Two new cases of stillborn conjoined twins were recently delivered at this hospital. The most common type and the ones most likely to be born alive were the omphalopagi. Surgical separation was successful in 5 cases but the twins separated at Zaria died about a month later. Emergency operations were performed on the pygopagus and ischiopagus, and one member of the former but both of the latter died. The thoracopagus and dicephalus twins were stillborn. However, necropsy findings in one of the thoracopagi indicate that surgical separation would have been feasible had the twins been born alive. The internal mechanical factors causing cardiac defects in such twins may be relevant to the study of the pathogenesis of congenital cardiac malformations.
Modern medicine wields the power to treat large numbers of diseases and injuries most of us would have died from just a hundred years ago. In view of this tremendous achievement, it can seem as if progress has slowed, and we have been unable to impact the most devastating diseases of our time. Chronic diseases of age such as cardiovascular disease, diabetes, osteoarthritis, or Alzheimer’s disease turn out to be of a complexity that may require transformative ideas and paradigms to understand and treat them. Parabiosis, which mimics aspects of the naturally occurring shared blood supply in conjoined twins in humans and certain animals, may just have the power to be such a transformative experimental paradigm. Forgotten and now shunned in many countries, it has contributed to major breakthroughs in tumor biology, endocrinology, and transplantation research in the past century, and a set of new studies in the US and Britain report stunning advances in stem cell biology and tissue regeneration using parabiosis between young and old mice. We review here briefly the history of parabiosis and discuss its utility to study physiological and pathophysiological processes. We argue that parabiosis is a technique that should enjoy wider acceptance and application, and that policies should be revisited especially if one is to study complex age-related, chronic disorders.
To determine whether twins born second are at increased risk of perinatal death because of complications during labour and delivery.
Retrospective cohort study.
Scotland, 1992 and 1997.
All twin births at or after 24 weeks' gestation, excluding twin pairs in which either twin died before labour or delivery or died during or after labour and delivery because of congenital abnormality, non-immune hydrops, or twin to twin transfusion syndrome.
Main outcome measure
Delivery related perinatal deaths (deaths during labour or the neonatal period).
Overall, delivery related perinatal deaths were recorded for 23 first twins only and 23 second twins only of 1438 twin pairs born before 36 weeks (preterm) by means other than planned caesarean section (P>0.99). No deaths of first twins and nine deaths of second twins (P=0.004) were recorded among the 2436 twin pairs born at or after 36 weeks (term). Discordance between first and second twins differed significantly in preterm and term births (P=0.007). Seven of nine deaths of second twins at term were due to anoxia during the birth (2.9 (95% confidence interval 1.2 to 5.9) per 1000); five of these deaths were associated with mechanical problems with the second delivery following vaginal delivery of the first twin. No deaths were recorded among 454 second twins delivered at term by planned caesarean section.
Second twins born at term are at higher risk than first twins of death due to complications of delivery. Previous studies may not have shown an increased risk because of inadequate categorisation of deaths, lack of statistical power, inappropriate analyses, and pooling of data about preterm births and term births.
What is already known on this topicIt is difficult to assess the wellbeing of second twins during labourDeliveries of second twins are at increased risk of mechanical problems, such as cord prolapse and malpresentation, after vaginal delivery of first twinsIncreased risks of perinatal death in second twins have not been shown, but the methods of these studies were flawedWhat this study addsSecond twins delivered at term are at increased risk of delivery related perinatal deathsIntrapartum anoxia caused 75% of these deaths in second twins, and most of these resulted from mechanical problems after vaginal delivery of first twinsPlanned caesarean section of twins at term may prevent perinatal deaths
Cases of conjoined twins occur so rarely that it is important to learn as much as possible from each case.
We present a case of 9-hour-old, female, Nigerian dicephalus parapagus conjoined twins discordant for anencephaly diagnosed only after the birth of the twins. The anencephalic twin was stillborn while the normal one died within 9 hours of birth from cardiopulmonary failure.
Many congenital defects of interest can now be detected before birth. A severe lesion such as that found in our index case, which is incompatible with postnatal life, requires counselling. If detected early enough during a properly monitored antenatal care, it may indicate termination of pregnancy.
Conjoined twins are rare variants of monozygotic twins, which result from an incomplete division of the embryonic disk. Cephalothoracopagus is a rare twin pregnancy described as imperfect fusion of the head and chest, but separated columns, limbs, and pelvis. They occur with incidence rates that range from 1 per 50,000 to 1 per 100,000 births; however, the incidence of the cephalothoracopagus variety is 1 per 58 conjoined twins. In the case of identical and symmetric faces caused by the orientations of the 2 notochordal axes that are perfectly ventroventral, they are called janiceps disymmetros. We present a prenatal diagnosis of a typical case of cephalothoracopagus janiceps disymmetros and the diagnostic confirmation by image and pathology exams.