Most Unusual Twin Pairs: A Look at Uterus Didelphys / Twin Research Reviews: Prenatal Aneuploidy Screening for Twin Pregnancies; Twin Conceptions by Same-Sex Male Couples; Legal Personality of Conjoined Twins; Twin Study of Cannabis Use / Human Interest and Importance: Being Taken for Twins Saved Sisters; Twin Children of Jailed Nobel Prize Winner; British 'Biracial' Twins; Triplets Born at Start of Russian Attack on Ukraine; Twins Born in Different Years.

A review of an unusual twin type-twins born to women with two uteri (uterus didelphys)-is presented. This review is followed by summaries of recent research and perspectives concerning prenatal aneuploidy screening for twin pregnancies, twin conceptions by same-sex male couples, legal personality of conjoined twins, and a twin study of cannabis use. Interesting information about twins that has appeared in the media is also presented, namely how being taken for twins saved a pair of sisters; twin children of a jailed Nobel Prize winner, British 'biracial' twins, triplets born at the start of Russia's attack on Ukraine, and twins born in different years.

Integrated multiomics reveal the molecular characteristics of conjoined twin fetuses.

RESEARCH QUESTION: Are there any differences between conjoined twin fetuses at the molecular level? DESIGN: Skin tissues were collected from thoracopagus conjoined twins at 15+4 weeks of gestation. The skin tissues were collected from the thigh side of conjoined twins after the abortion procedure. All specimens were obtained after written informed patient consent and were fully anonymized. All relevant ethical regulations were followed. Every specimen underwent multiomics sequencing analysis to determine associations among the DNA methylome, transcriptome and mutations in the exon regions in the conjoined twins. RESULTS: The global methylation pattern was similar in the two fetuses of conjoined twins, while significant differences were seen in local regions such as CpG islands (P = 0.026), enhancers (P < 0.001) and various repetitive elements (P < 0.05), which showed significant differences. The conjoined twins also differed in genes related to growth and development, cellular component morphogenesis and cellular stress, both in terms of DNA methylation levels and gene expression levels. Exon data analysis revealed that the common mutations in conjoined twins mainly occurred in neural development, lipid metabolism and microtubule morphogenesis. Specific mutations were associated with cellular component biosynthesis, behaviour and germ cell development. CONCLUSION: Conjoined twins were similar to each other globally, but there were significant differences related to growth and development, cellular component morphogenesis and cellular stress. The current study reveals the molecular features of conjoined twins for the first time, laying the foundation for future exploration of the mechanism of conjoined twins.

Twin Research and Human Genetics - News, Views & Comments: Memoirs and Autobiographies by Twins: Research Angles and Human Interest/Twin Research Reviews: Fetal Reduction in Twin Pregnancy; Twins' Personality and Military Service; Growth Restriction in Twins; Advances in Conjoined Twin Separation/Media Reports: Update on Scientist Who Performed Gene Editing on Twins; Twins From 33-Year-Old Embryos; Twins' Outcomes From Dietary Differences; Fraternal Twins With the World's Largest Height Difference; Twin Home Experts Conquer Rat Infestation.

Twins' memoirs and autobiographies both enlighten and entertain. These works, often overlooked by researchers, may suggest new avenues for investigation, such as nonshared environmental events that propel twins in different directions. Of course, MZ twins' generally parallel experiences and DZ twins generally criss-crossing paths are the bases of fascinating life stories. The following sections examined recent research on fetal reduction in twin pregnancy, twins' personality and military service, growth restriction in twins, and advances in conjoined twin separation. This article closes with reports of a scientist who performed gene editing on twins, a twin conception from 33-year-old embryos, twins' physical outcomes from dietary differences, fraternal twins with the world's largest height difference and the Twin Home Experts who conquer rat infestation in New York.

Separation of conjoined spinal cords in symmetrical pygopagus twins using intraoperative neuromonitoring: pearls and pitfalls.

Pygopagus twin is a rare congenital malformation with a worldwide incidence of 1in 200,000. Few literature reports are published regarding the matter. In some cases, neuromonitoring is essential for safe surgical separation. We believe it is important to share our challenges and nuances in order to minimize obstacles one might encounter. We utilized neuromonitoring during our separation of both twins, and we planned a multidisciplinary approach and efficient communication system with the other teams in order to plan a successful, safe, and timely separation of the twins. We seek to highlight not our success but rather the obstacles and challenges we encountered during the separation of pygopagus twins in our institute using neuromonitoring for future reference.

The role of intraoperative neuromonitoring in pygopagus separation: two-institution experience in Indonesia.

INTRODUCTION: Pygopagus comprises 17% of all conjoined twin cases. Survival rate is higher compared to other variations of conjoined twins, but separation is a great challenge due to multiorgan involvement. Intraoperative neuromonitoring (IONM) used aims to aid operator in preserving as much function as possible. CASE PRESENTATIONS: The authors reported 2 pairs of pygopagus separation. Intraoperatively, motor-evoked potential (MEP) and sensory-evoked potential (SEP) were used in all patients. Three patients survived in which all had transient motor deficits. Urinary retention was reported in one patient. One patient died 2 weeks after separation as twins only had one kidney which was spared for the healthier twin. DISCUSSION: IONM was used to guide operator in dissecting, identify the ownership of the neural structures, and determine the safest point to separate in pygopagus separation. Despite the normal MEP and SEP recordings, transient motor weakness may still occur transiently. The motor tract development of children is achieved in adolescence, making MEP less accurate. However, the reliability of MEP increases when it is combined with SEP. Autonomic function monitoring such as bulbocavernosus reflex (BCR) could not be assessed due to the unavailability of the probe. CONCLUSION: IONM can aid operator in pygopagus separation during determining the origins of the structure, dissecting, and cutting the neural structures. Normal MEP interpretations are still possible to correlate with transient deficits, but reliability can be improved with the use of SEP. In surgeries involving the lower spine level, BCR monitoring is recommended to avoid autonomic deficits.

Postnatal imaging of conjoined twins: a customized multimodality approach.

Medical imaging plays a crucial role in the management of conjoined twins. The role of imaging is to explore the anatomy, outline the shared organs and determine whether surgery is feasible. It also serves as a roadmap for successful separation. Additionally, imaging helps with counseling parents about prognosis. This review aims to illustrate recent advances in different imaging modalities and their role in the management of the various types of conjoined twins with an emphasis on relevant tips for optimal imaging.

Emergency separation of conjoined twins in a tertiary hospital in Indonesia: three case reports.

BACKGROUND: Emergency separation of conjoined twins is performed when one twin is already dead or dying and threatens the survival of the other. The particular decision to perform an emergency separation of conjoined twins provides an ethical dilemma that needs special attention. Adding to the complexity of surgical and postsurgical management in emergency separation, ethical and sociocultural aspects further complicate decision-making. CASE PRESENTATION: From 1987 to 2022, 18 conjoined twin separations were performed in our centre. This paper describes three conjoined twin emergency separations. In the first case of thoracoomphalopagus babies at nine days of age, one baby was diagnosed with necrotizing enterocolitis with frequent desaturation and seizures, and the other baby was healthy. Emergency separation was performed on the twelfth day of age; unfortunately, neither baby survived the surgery. In the second case, emergency separation was performed on the 110th day of life due to sepsis in one baby. The nonseptic twin passed away six hours after surgery, while the septic twin died 12 days after surgery due to wound dehiscence and abdominal sepsis. The third case was of an omphalopagus conjoined twin with a parasitic twin. The healthy baby was deemed nonviable but found to be healthy upon birth. Immediate emergency separation was performed at 2 h of age. The living baby survived the surgery but passed away two months later. CONCLUSIONS: When separation is deemed necessary to save one twin, it becomes difficult to apply standard ethical medical reasoning. The decision to separate results in most cases in very high-risk surgeries with poor outcomes during surgery and postsurgery. Compounded by the complexity of the case, sociocultural and religious aspects further add to the dynamics of decision-making. A multidisciplinary team must work together with a health ethics committee and navigate through this ethical conundrum with the patient and family at its decision-making centre to decide on the best plan of care.

Anterior Chest Wall Reconstruction After Separation of Thoraco-Omphalopagus Conjoined Twins With Cadaveric Rib Grafts and Omental Flap.

BACKGROUND: Anterior chest wall defects have a wide range of etiologies in the pediatric population, ranging from infection, tumor, and trauma to congenital diseases. The reconstructive goals include restoring skeletal stability, obliterating dead space, preserving cardiopulmonary mechanics, and protecting vital underlying mediastinal organs. Although various reconstructive methods have been described in the literature, selecting the optimal method is challenging for the growing pediatric skeleton. Here, we report a case of previously thoraco-omphalopagus twins who underwent successful separation and reconstruction and presented for definitive anterior chest wall reconstruction. METHODS: A pair of previously thoraco-omphalopagus conjoined twins underwent definitive anterior chest wall defect reconstruction using cadaveric ribs and omental flap. Twin A received 2 cadaveric ribs, whereas twin B had a much larger sternal defect that required 3 cadaveric ribs combined with an omental flap for soft tissue chest coverage. Both twins were followed up for 8 months. RESULTS: Twin A's postoperative course was uneventful, and she was discharged on postoperative day 6. Twin B's course was complicated, and she was discharged on supported ventilation on postoperative day 10. At 8 months postoperatively, both twins healed well, and chest radiographs confirmed the stability of the chest reconstructions. The rib grafts in the twin with a tracheostomy were not mobile, and the patient had a solid sternum with adequate pulmonary expansion. The construct initially did not facilitate pulmonary functioning, but after a healing process, it eventually allowed for the twin with the tracheostomy who required pulmonary assistance to no longer need this device. CONCLUSIONS: Cryopreserved cadaveric ribs and omental flaps offer safe and reliable reconstructive methods to successfully reconstruct congenital anterior chest wall skeletal defects in the growing pediatric population. The involvement of multidisciplinary team care is key to optimizing the outcomes.

The Management of Acardiac Twinning: Twin Reverse Arterial Perfusion Sequence - An International Survey.

INTRODUCTION: The optimal approach and therapy method for the acardiac twin with a reverse arterial perfusion sequence has not yet been established. The aim of this study was to determine the clinical practice patterns among international fetal therapy units in their management of these cases. METHODS: A survey was sent to fetal centers across the world via email between December 2020 and December 2021. RESULTS: Responses were obtained from 77% contacted centers. The most frequent ultrasound variables used in the evaluation of twin reverse arterial perfusion sequence include echocardiographic assessment of the pump twin and umbilical artery Doppler waveforms in the acardiac and pump twins, in 90% and 80% of the centers, respectively. Most centers in Europe and Latin America propose an in utero intervention in all cases. Most centers in Europe and Latin America prefer interstitial laser ablation, whereas radiofrequency ablation (RFA) is preferred in North America. The earliest gestational age for an intervention is on mean 13 weeks in Europe, which is earlier than the other geographic areas (p = 0.001). CONCLUSIONS: Most centers agreed that antenatal evaluation should include echocardiography along with the UA Doppler waveform measurements, and the most frequently used interventions were interstitial laser ablation or RFA at a median between 14 and 26 weeks.

Thoracopagus conjoined twins.

OBJECTIVE: We present a case report of conjoined twins. CASE REPORT: Secundigravida nullipara, 28-years old, admitted for profuse bleeding at 13 weeks of gestation. Ultrasound confirmed vital pregnancy of conjoined twins - thoracopagus. After prenatal diagnostic consultation the patient decided for termination of pregnancy. Molecular analysis confirmed a female fetus without any chromosomal anomalies. CONCLUSION: The occurrancce of conjoined twins is very rare. Early prenatal ultrasound diagnosis plays an important role. Presented case report describes conjoined twins with poor prognosis because of one shared malformed heart.

Separation of Craniopagus Twins by a Multidisciplinary Team.

Conjoined twins who are classified as craniopagus (joined at the cranium) have a rare congenital anomaly. Despite advances in surgical techniques and critical care, the rate of complications and death is still high among twins with total fusion in which the superior sagittal sinus is shared. Here, we describe total-fusion craniopagus twins who at 10 months of age underwent successful surgical separation performed by a multidisciplinary team. Computer-aided design and modeling with a three-dimensional printer, custom-designed cranial distraction and constriction devices, and intraoperative navigation techniques were used. These techniques allowed for separation of the twins at an early age and harnessed the regenerative capacity of their young brains.

Conjoined twins after single blastocyst transfer: a case report including detailed time-lapse recording of the earliest embryogenesis, from zygote to expanded blastocyst.

Conjoined twins are estimated to occur in 1:50 000 pregnancies. Eighteen cases of pregnancies achieved by ART have been published of which three were achieved after single embryo transfer, allowing discussion of embryo characteristics. We report, to the best of our knowledge, the first case of parapagus conjoined twins after ART. Furthermore, this is the first report of conjoined twins with detailed morphokinetics of the earliest embryogenesis from zygote to expanded and hatched blastocyst stage. The case zygote had three refractile bodies, which were all allocated to one blastomere at first cleavage following an asynchronous pronuclei fading. Within 2 h, this blastomere cleaved to four and fragmented. The remaining blastomere cleaved symmetrically and regularly and a blastocyst (score: 4AB) was vitrified 120 h after IVF. Pregnancy was achieved following a frozen-thawed single blastocyst transfer. The etiopathogenetic mechanism of the origin of conjoined twins is unknown and several hypotheses exist. The morphokinetics in the present case and morphology of other reported cases will be discussed in this context.

The role of the University of Padua medical school in the study of conjoined twins between 18th and early 19th century.

The Medical School of Padua (Italy) contributed profoundly to the study of teratology. Many famous physicians and professors of medicine, such as Liceti, Vallisneri, Morgagni, and Malacarne, have studied and investigated these anomalies to better understand the causes and to find a potential explanation, often preserving the specimens for future studies. The present study highlights some historical cases of conjoined twins and a conjoined triplet preserved at the Morgagni Museum of Human Anatomy to show the development of medical theories in the teratological field between the 18th and early 19th century. This approach will provide insights into different study methods and ideas of some of the most famous scholars working in Padua at that time. The current article focuses on rare cases, both human and animal, that were encountered by physicians who worked in the Veneto area in the late 18th and early 19th century. Their detailed descriptions are not only of historical but also of contemporary dysmorphological value.

Reared-Apart and Reunited: Extraordinary Dynamics/Twin Research Reviews: Twin Bereavement and Lifespan Associations; Identifying Novel Mutations in Twins; Parenting Premature Multiples; Conjoined Twins in Cross-Cultural Context/In the News: Madeline Albright, Mother of Twins, Passes Away; Identical Twin Songwriters Compose New Musical; Visually Impaired Twin Skiers; Identical Twin Brothers Undergo Heart Transplants; Naming the Genain Quadruplets.

The focus of this article is on insights gained from the extraordinary dynamics that took place between a pair of reunited monozygotic female twins from Greece. Topics include visualizing the co-twin prior to meeting, the unique love and attraction between the twins, a mother's response to discovering her child's cotwin and the challenges posed by insufficient kinship categories. The following section of this article surveys four recent twin research reports. They include Bereavement and Lifespan Associations; Novel Mutations in Twins; Parenting Premature Multiples; and Conjoined Twins. The final part of this article presents interesting and informative news about twins from popular sources. The topics covered are the passing of Madeline Albright (Secretary of State and mother of twins); identical twin songwriters; visually impaired twin and sibling skiiers; identical twin brothers who both received heart transplants; and the naming of the Genain quadruplets.

Quadruplets: Risks, Outcomes and a Set of Four/Twin Research Reviews and a Lawsuit: Antenatal Corticosteroids and Twins' Neonatal Outcomes; Fathers of Twins; Doppelgängers and Similarity; Monozygotic Co-Twin Difference in Asymmetric Pigmented Paravenous Chorioretinal Atrophy/In the News: Opposite-Sex Twin Holocaust Survivors; Twin Models at Gucci; Twins With Different Fathers; Reunited Twins Enter Same Convent; Death of a Twin Soldier During Training; Surgical Separation of Conjoined Twins.

Quadruplets are at elevated physical risks at prenatal, perinatal, and postnatal levels, relative to twins. A brief review of this area is followed by discussion of a female quadruplet with three co-quadruplet brothers. Next, several timely twin research reports are examined. The topics include antenatal corticosteroids and twins' neonatal outcomes, the meaning of fatherhood in families with twins, what doppelgängers (look-alikes) reveal about physical and behavioral similarity, and monozygotic (MZ) co-twin discordance for asymmetric pigmented paravenous chorioretinal atrophy. A lawsuit involving alleged cheating on a medical school examination by identical twins is also reviewed. General interest stories cover opposite-sex twin Holocaust survivors, twin models at a Gucci fashion show, twins with different fathers, reunited female twins who entered the same convent, the death of an MZ female twin soldier during training, and the surgical separation of conjoined twins in Brazil.

Heteropagus twins: six cases with systematic review and embryological insights.

PURPOSE: Heteropagus twinning (HT) is a rare anomaly. Six new cases along with a systematic review are described. METHODS: Six cases of HT managed at two tertiary care teaching hospitals over the last 26 years are described. A PubMed search with words: Heteropagus AND/ OR parasitic twins from 2001 to 2021 hit 183 articles. 36 were added from non-PubMed sources. Finally, 120 cases including 114 from 69 articles and 6 new cases were analysed. RESULTS: Of the new cases, 2/6 had an antenatal diagnosis. Five were males. 4 autosites had omphaloceles. Split notochord and 2 parasites attached to a single autosite were encountered. 5/6 autosites survived. On systematic review, the most frequent variant seen was rachipagus (n = 50) followed by omphalopagus (n = 46). Limbs were reported in 75 cases. Congenital heart disease was seen in 17/120(14.2%) autosites. Omphalocele and meningomyelocele were the most common extracardiac anomalies in autosites. Weight along with the anatomy and position of heteropagus twins was a better determinant of the mode of delivery than weight alone. Mortality was reported in 12 cases. CONCLUSION: Autosites in HT generally carry a good prognosis, however, final outcome depends mainly on associated major cardiac anomalies. Meticulous antenatal assessment and preoperative planning are of paramount importance. LEVEL OF EVIDENCE: IV.

A cohort of five cases with asymmetric conjoined twining and literature review.

PURPOSE: Asymmetric conjoined twining (ACT) is a form of conjoined twining which is a rare malformation of monochorionic monoamniotic twin pregnancy. Most publications were single case reports. We reported a cohort of five cases with ACT from a single tertiary medical center and reviewed the case reports of ACT over the last decade to enrich the clinical research of this disease and summarized the clinical features of the disease. METHODS: We reviewed five cases of ACT admitted in Tianjin Children's Hospital from 17 March, 2008, through 7 March 2017. The cohort was analysed from general information, imaging manifestations, separation surgery, histopathological findings, outcome and follow-up. We searched the English literatures on case reports of ACT over the past decade from the PubMed database and presented details about the clinical characteristics, treatment, and prognosis of all cases. RESULTS: There were four males and one female in our cohort. Among the five cases, two parasites were located in epigastrium, two in rachis, and one in retroperitoneum (fetus in fetu, FIF). All of the parasites were separated successfully by operation in five cases and were confirmed to be ACT by histopathology reports. Four patients made an uneventful recovery except for one case of wound infection. All of them were doing well in follow-up. In the literature review, we found 41 cases of exoparasitic heteropagus twining (EHT) and 63 cases of FIF. CONCLUSIONS: ACT is very rare and usually diagnosed by prenatal ultrasonography (US). Computed tomography (CT) and magnetic resonance imaging (MRI) examinations are essential imaging examinations before separation surgery to delineate the anatomical relationship between the autosite and the parasite. In general, the separation surgery of ACT is less complicated and the prognosis is better compared with the symmetric conjoined twining (SCT).

Cephalothoracoomphalopagus - a rare type of conjoined twins from the pathologists perspective.

Objective: Case description and autopsy fi nding in conjoined twins dia gnosed in the 24th week of pregnancy. Results: We reporta case of a 31-year-old primigravida who was referred to the Department of Gynecology and Obstetrics at our hospital with a presumptive dia gnosis of conjoined twins. The ultrasound examination with subsequent three-dimensional (3D) image reconstruction demonstrated twin gestation complicated by cephalothoracoomphalopagus. Observations demonstrated that the twins were joined over an area that extended from the head to the thoraces down to the central abdomen. In view of multiple congenital malformations incompatible with postnatal life, the pregnancy was terminated. The twins then underwent an autopsy at the Department of Pathology and the autopsy confi rmed previous diagnosis. Conclusion: Cephalothoracoomphalopagus is one of the rarest forms of conjoined twins with unknown incidence due to a very small number of documented cases.

Cross-cultural representations of conjoined twins.

Conjoined twinning is a rare birth defect estimated to occur in about 1 in 50,000 to 100,000 births. The mechanism of conjoined twinning is not proven. Different forms of conjoined twinning are observed with the thoracopagus form being the most common. The rate of conjoined twinning is similar across all major populations. A dramatic malformation of this type would be an extraordinary occurrence leading people to reflect on the spiritual or supernatural nature of such an event. Therefore, it is not surprising that artifacts that seem to depict different forms of conjoined twins are seen across diverse cultures. In this article, we present a survey of these cultural artifacts including anatomic classification based on external anatomy and an exploration of the cultural and spiritual contexts associated with the artifacts. A key finding is that the most common form of conjoined twinning in the artifacts is parapagus (both dicephalus and diprosopus) in contrast to thoracopagus, the most common form in epidemiologic studies. Potential reasons for this difference are discussed. Evidence is presented to support the speculation that these objects represent artistic impressions of actual conjoined twinning events.

Multiparametric Imaging for Presurgical Planning of Craniopagus Twins: The Experience of Two Tertiary Pediatric Hospitals with Six Sets of Twins.

Conjoined twins are rare and pose a challenge to radiologists and surgeons. Craniopagus twins, where conjunction involves the cranium, are especially rare. Even in large pediatric centers, radiologists are unlikely to encounter more than one such event in their medical careers. This rarity makes it daunting to select a CT and MRI protocol for these infants. Using the experience of two tertiary pediatric hospitals with six sets of craniopagus twins, this multidisciplinary and multimodal integrated imaging approach highlights the key questions that need addressing in the decision-making process for possible surgical intervention.