Monocephalic thoracopagus tetrabrachius in twin lambs

Bangabandhu Sheikh Mujib Medical University Journal, 2012

Conjoined twins are a rare and complex complication of monozygotic twinning, which is associated with high perinatal mortality. One of the commonest defects of blastogenesis is monozygotic twinning resulting in separate or conjoint twins. The latter includes category of internal, "endoparasitic," or fetus-in-fetu twins. 1 Conjoined twinning only arises when the twinning event occurs at about the primitive streak stage of development, at about 13-14days after fertilization, and is exclusively associated with monoamniotic monochorionic type. Conjoined twins (also known as Siamese twins) are identical twins whose bodies are joined in utero. It is a rare phenomenon, the occurrence is estimated to range from 1 in 50,000 to 1 in 100,000 births, with a somewhat higher incidence in Southwest Asia and Africa. 2 Approximately half are stillborn, and a smaller fraction of pairs born alive having abnormalities which is incompatible with life. The overall survival rate for conjoined twins is approximately 25%. The condition is more frequently found among females, with a ratio of 3:1. 2 Two contradicting theories exist to explain the origins of conjoined twins. The older and most generally accepted theory is fission, in which the fertilized egg splits partially. The second theory is fusion, in which a fertilized egg completely separates, but stem cells (which search for

International Journal of Reproduction, Contraception, Obstetrics and Gynecology, 2015

Conjoined twins are a rare occurrence with an incidence of about 1 in 100000 pregnancies. Our case is that of a 32 year old multigravida patient who came to us at 17 weeks gestation with a scan done at 14 weeks suggestive of severe spinal dysraphism with lumbar meningomyelocele spina bifida at multiple levels with protuberant abdomen. The patient opted for medical termination of pregnancy which was carried out after due to consent. The patient aborted after 12 hours. Further inspection of the abortus revealed it to be conjoined twins with one apparently normal head and thorax with a large omphalocele with 4 lower limbs. There were two caudal halves along with two sets of lower limbs and external genitalia arising from the abortus perpendicular to it on either side of the thorax. One set of arms was attached to the thorax and yet another arm and a limb bud were arising from the other end of the fetus attached to a rudimentary head like structure. Heteropagus tetrapus twins are an extremely rare form of parasitic twins. Inspite of advances in surgical techniques and methods, the morbidity endured by the affected neonates is very high. Thus prenatal diagnosis of conjoined twins along with the option of termination of pregnancy is of utmost importance.

Objective: To report an interesting incidental occurrence that may improve the understanding of the mysterious embryology of conjoined twins. Methodology: The embryos were generated in-vitro through intracytoplasmic sperm injection ICSI. On day 3 of embryo development, the Zona of each 8-cell embryo was breached with LASER and the embryos were cultured in pairs per well in a culture dish in preparation for herniation for a day 5 trophectoderm biopsy for Pre-Implantation Genetic Diagnosis. Results: On day 5, a particular pair of embryos was accidentally placed at very close proximity adjacent to each other. Interestingly, during herniation, the trophectoderm cells were observed to have joined and started developing together into " conjoined embryos ". Conclusion: The fact remains that there are more mysteries surrounding the origin or the embryology of conjoined twining. The current knowledge is that of two theories postulated of which the fission theory is the most widely accepted. This finding could support the fusion theory.

Journal of Chitwan Medical College, 2019

A 27 years old primigravida woman at 19 weeks of gestation was came for routine antenatal checkup in Chitwan Medical College was diag­nosed as twin pregnancy with thoracophagus conjoined twin. The fetal biometrics of both were consistent with the gestational age. Fetuses were found with fusion of the skin contour, at the level of the lower chest with complex appearing fused cardiac near midline and liver ap­pears separate. Both fetal heads were in breech presentation facing faces with each other at the same level. Bilateral upper and lower limbs were identified in both fetuses with same gender. The parents decided to terminate the pregnancy but refused autopsy.

Indian Journal of Radiology and Imaging, 2006

Teratology, 1980

Six pairs of conjoined twins have been studied. The first case was a pair of 13-week-old omphalopagus fetuses. One was a holoacradius amorphus and the other had rachischisis and anencephaly. The second case was a pair of omphalopagus twins. One of the twins was macerated and corresponded to a developmental age of 13-14 weeks, while the other was developed to 28-30 weeks of gestation and exhibited urogenital and gastrointestinal defects not found in the smaller twin. In the third case, that of a thoracoomphalopagus. one had cleft lip and palate, pulmonic stenosis, and atresia of the ileocecal valve, while the other did not show these anomalies. In the fourth case, also omphalopagus twins, one had a lumbosacral meningomyelocele and severe gastrointestinal and urogenital anomalies not found in the second twin. The fifth case was a pair of thoracoomphalopagus twins, sharing a common heart with asymmetrical anomalies. The sixth case was a diprosopus anencephalic conjoined twin. The first four pairs of conjoined twins were discordant for several abnormalities in nonshared organs, in addition to having abnormalities of the conjoined organs. I t seems that discordance in conjoined twins is not a rare finding. The factors that play a role in discordance of anomalies in conjoined twins are probably similar to the factors in monozygotic twinsi.e., environmental, genetic, and abnormal placental andlor fetal circulation.

International Journal of Reproduction, Contraception, Obstetrics and Gynecology, 2014

Conjoined twins are among rare clinical conditions observed by obstetricians. Due to rare incidence of this condition there is general lack of knowledge among obstetricians, especially at primary care level which leads to missed diagnosis during antenatal period. The management of this condition is complex especially in cases where the diagnosis is not known before onset of labour. A 30-year old Hindu lady was referred to us from other hospital with diagnosis of twin pregnancy and prolonged second stage of labour. Clinical examination revealed findings of ruptured uterus and foetal head of one baby and feet of second baby were outside the introitus. Emergency laparotomy was done which revealed conjoined twins. This article report clinical course of a thoracopagus conjoined twin. The relevant literature is also reviewed.

American Journal of Obstetrics and Gynecology, 1976

International Journal of Surgery Case Reports, 2020

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Medical Science

Conjoined twins are a relatively uncommon congenital anomaly with a significant mortality and morbidity rate. Twins who are conjoined are the thoracopagus variation is one of the most common types of conjoined twins, in which the fusion is anterior, at the chest and affects the heart. We describe a case of a 19 years old primigravida who delivered conjoined twins by thoracopagus. A pregnant woman who had reached full cervical dilatation was admitted to the delivery room. She had an ultrasound, which revealed bigeminal pregnancy with two breech-presented foetuses that were perhaps conjoined twins. The foetus' dimensions determined by ultrasound corresponded to a gestational age of 22 weeks. The first foetus' heart rate was roughly 40 beats per minute, while the second foetus' heart rate was imperceptible. She delivered herself by manually extracting the foetuses. Unable to show any signs of life, one male and one female foetus were delivered. The cause of death was determined by autopsy to be thoracophagus.