Novel autopsy and genetic findings in an acardiac twin: case report and literature review.

Twin reversed arterial perfusion (TRAP) sequence is a rare complication of monochorionic twinning whereby a donor twin perfuses an acardiac twin via aberrant vascular anastomoses. The resulting paradoxical retrograde blood flow supplying the acardiac twin is oxygen-poor, leading to some of the most severe malformations encountered in humans. Though the first descriptions of acardiac twins date back to at least the 16th century, the pathophysiologic processes which underpin the development of TRAP sequence are still being elucidated. Theories on the pathogenesis of TRAP sequence include deficiencies intrinsic to the embryo and primary abnormalities of the placental vasculature. Autopsy studies continue to provide clues to the underlying pathogenesis of TRAP sequence, and the characterization of the spectrum of manifestations that can be observed in acardiac twins. Herein, we present the clinical, autopsy, and molecular findings in a unique case of TRAP sequence. Novel findings include a primitive cloaca-like structure and chromosomal aberrations involving 6q11.1 and 15q25.1.

Bilateral Peters' anomaly, aniridia and Wilms tumour (WAGR syndrome) in monozygotic twins.

AIM: This study reports the bilateral association of Peters' anomaly and congenital aniridia in monozygotic twins subsequently diagnosed with Wilms tumour (WAGR syndrome). METHODS: Two monozygotic female twins were referred at age 2 months with bilateral corneal opacity. A diagnosis of Peters' anomaly associated to aniridia was made in both eyes of both twins. Physical examination and ultrasonography were carried out at 12 months of age to explore the possibility of WAGR-related anomalies, specifically Wilms tumour. DNA were isolated and subjected to whole exome sequencing. RESULTS: Peters' anomaly associated to aniridia in both eyes as well as bilateral Wilms tumour in both children were diagnosed. Exome analyses showed a large heterozygous deletion encompassing 6 648 473 bp in chromosome 11p13, using Integrative Genomics Viewer and AnnotSV software. CONCLUSION: WAGR syndrome is a rare contiguous gene deletion syndrome with a greater risk of developing Wilms tumour associated with Peters' anomaly and congenital aniridia. However, co-occurrence of both anomalies was rarely reported in twins, and never in both eyes of monozygotic twins. Here, we report the bilateral association of Peters' anomaly and congenital aniridia in monozygotic twins with WAGR syndrome.

Monochorionic triplet pregnancy complicated by conjoined twins and early twin-twin transfusion syndrome.

BACKGROUND: The condition of monozygotic, monochorionic triplet fetuses with a pair of conjoined twins is extremely rare (close to one in a million births), presents challenges in its management, and with poor prognosis. CASE REPORT: We report a case of monochorionic diamniotic triplet pregnancy, ultrasound at 14 weeks shows a pair of conjoined thoracopagus fetuses, sharing heart, liver, and umbilical cord, in addition to omphalocele. The third fetus, without malformations, presents signs of early heart failure compatible with twin-to-twin transfusion syndrome. It was decided to carry out expectant management where at 18 weeks, intrauterine death of the three fetuses occurs. An abortion is performed by hysterotomy. CONCLUSIONS: The treatment in these cases is discussed, three management options have been proposed: expectant management, selective reduction of the conjoined fetuses, or termination of the pregnancy. A review of the literature found only 12 cases with this combination of pathologies, in which only 3 normal fetuses (25%) survived and none of the conjoined twins survived. To our knowledge, this case is the first of a monochorionic triplet pregnancy with conjoined fetuses complicated with early twin-to-twin transfusion.

Novel autopsy and genetic findings in an acardiac twin: case report and literature review

ABSTRACT Twin reversed arterial perfusion (TRAP) sequence is a rare complication of monochorionic twinning whereby a donor twin perfuses an acardiac twin via aberrant vascular anastomoses. The resulting paradoxical retrograde blood flow supplying the acardiac twin is oxygen-poor, leading to some of the most severe malformations encountered in humans. Though the first descriptions of acardiac twins date back to at least the 16th century, the pathophysiologic processes which underpin the development of TRAP sequence are still being elucidated. Theories on the pathogenesis of TRAP sequence include deficiencies intrinsic to the embryo and primary abnormalities of the placental vasculature. Autopsy studies continue to provide clues to the underlying pathogenesis of TRAP sequence, and the characterization of the spectrum of manifestations that can be observed in acardiac twins. Herein, we present the clinical, autopsy, and molecular findings in a unique case of TRAP sequence. Novel findings include a primitive cloaca-like structure and chromosomal aberrations involving 6q11.1 and 15q25.1.

Lab partners: oocytes, embryos and company. A personal view on aspects of oocyte maturation and the development of monozygotic twins.

The present review addresses the oocyte and the preimplantation embryo, and is intended to highlight the underlying principle of the "nature versus/and nurture" question. Given the diversity in mammalian oocyte maturation, this review will not be comprehensive but instead will focus on the porcine oocyte. Historically, oogenesis was seen as the development of a passive cell nursed and determined by its somatic compartment. Currently, the advanced analysis of the cross-talk between the maternal environment and the oocyte shows a more balanced relationship: Granulosa cells nurse the oocyte, whereas the latter secretes diffusible factors that regulate proliferation and differentiation of the granulosa cells. Signal molecules of the granulosa cells either prevent the precocious initiation of meiotic maturation or enable oocyte maturation following hormonal stimulation. A similar question emerges in research on monozygotic twins or multiples: In Greek and medieval times, twins were not seen as the result of the common course of nature but were classified as faults. This seems still valid today for the rare and until now mainly unknown genesis of facultative monozygotic twins in mammals. Monozygotic twins are unique subjects for studies of the conceptus-maternal dialogue, the intra-pair similarity and dissimilarity, and the elucidation of the interplay between nature and nurture. In the course of in vivo collections of preimplantation sheep embryos and experiments on embryo splitting and other microsurgical interventions we recorded observations on double blastocysts within a single zona pellucida, double inner cell masses in zona-enclosed blastocysts and double germinal discs in elongating embryos. On the basis of these observations we add some pieces to the puzzle of the post-zygotic genesis of monozygotic twins and on maternal influences on the developing conceptus.

Corrigendum: Follow-up of young adult monozygotic twins after simultaneous critical coronavirus disease 2019: a case report.

[This corrects the article DOI: 10.3389/fmed.2022.1008585.].

Takayasu's Arteritis in Mexican Monozygotic Twins: Analysis of Human Leukocyte Antigens (HLA) Haplotypes.

Takayasu's arteritis (TA) is an idiopathic great vessel vasculitis that affects the aorta and its branches. This entity is associated with the major histocompatibility complex (MHC) genes. We studied DNA sequences of human leukocyte antigens (HLA) haplotypes in one pair of Mexican monozygotic twins affected by TA. HLA alleles were determined by sequence-specific priming. Genetic testing of the HLA haplotypes in both sisters were A*02 B*39 DRB1*04 DQB1*03 : 02/A*24 B*35 DRB1*16 DQB1*03 : 01. These results confirm that within the MHC are genes that determine genetic susceptibility to develop TA and sustain genetic heterogeneity of this disease among populations.

Perinatal Outcomes In Monozygotic Pregnancies Resulting From Assisted Reproductive Technology Procedures: A Single-Center 6-Year Experience Based On A Large Cohort Of Pregnancies.

OBJECTIVE: Monozygotic twin (MZT) pregnancies increase the risk of maternal and infant mortality and include many complications. The present study describes our assisted reproductive technology (ART) procedures from the viewpoint of perinatal outcomes in MZT pregnancies. METHODS: In this retrospective clinical cross-sectional study, 1159 in vitro fertilization (IVF) cycles performed between October 2014 and December 2019 were reviewed and perinatal outcomes and general clinical conditions analyzed. RESULTS: Sixteen MZT pregnancies were observed, resulting in an incidence of 1.38%. The MZT pregnancy incidence for patients aged ≤35 and >35 years were 0.2% and 1.1%, respectively. Eight MZT pregnancies resulted in live births, while five ended in miscarriage. A significant positive correlation was found between the number of attempts and the age of female (r:0.674; p=0.004) and male (r:0.657; p=0.006) partners. Cumulus-Oocytes Complexes (COC) (r:0.635; p=0.008), Metaphase II Oocyte (MIIO) (r:0.627; p=0.009), Pronucleus Oocyte (PO) (r:0.585; p=0.017) were correlated with serum AMH levels. The number of MZT was positively correlated with male partner age (r:0.527; p=0.036) and negatively correlated with embryo transfer day (ETd) (r:-0.548; p=0.028). CONCLUSIONS: The incidence of MZT pregnancies observed in this study was similar to the incidence reported in the literature, although risk was more pronounced among women aged >35 years. Due to potential risks for mothers and fetuses, MZT pregnancies may become a problem as the number of individuals seeking IVF continues to increase.

Lab partners: oocytes, embryos and company. A personal view on aspects of oocyte maturation and the development of monozygotic twins

The present review addresses the oocyte and the preimplantation embryo, and is intended to highlight the underlying principle of the "nature versus/and nurture" question. Given the diversity in mammalian oocyte maturation, this review will not be comprehensive but instead will focus on the porcine oocyte. Historically, oogenesis was seen as the development of a passive cell nursed and determined by its somatic compartment. Currently, the advanced analysis of the cross-talk between the maternal environment and the oocyte shows a more balanced relationship: Granulosa cells nurse the oocyte, whereas the latter secretes diffusible factors that regulate proliferation and differentiation of the granulosa cells. Signal molecules of the granulosa cells either prevent the precocious initiation of meiotic maturation or enable oocyte maturation following hormonal stimulation. A similar question emerges in research on monozygotic twins or multiples: In Greek and medieval times, twins were not seen as the result of the common course of nature but were classified as faults. This seems still valid today for the rare and until now mainly unknown genesis of facultative monozygotic twins in mammals. Monozygotic twins are unique subjects for studies of the conceptus-maternal dialogue, the intra-pair similarity and dissimilarity, and the elucidation of the interplay between nature and nurture. In the course of in vivo collections of preimplantation sheep embryos and experiments on embryo splitting and other microsurgical interventions we recorded observations on double blastocysts within a single zona pellucida, double inner cell masses in zona-enclosed blastocysts and double germinal discs in elongating embryos. On the basis of these observations we add some pieces to the puzzle of the post-zygotic genesis of monozygotic twins and on maternal influences on the developing conceptus.(AU)

Análise de métodos de identificação humana para diferenciação de gêmeos monozigóticos: revisão de literatura / Analysis of human identification methods for differentiating monozygotic twins: a literature review

Devido à dificuldade de diferenciação entre gêmeos monozigóticos (GM) e as limitações existentes nos métodos, decorrentes das influências e similaridades genéticas, ambientais e faciais, a busca por métodos confiáveis que possam distinguir esses indivíduos geneticamente idênticos torna-se de grande importância para o campo forense. O objetivo deste trabalho foi realizar uma revisão da literatura do tipo narrativa a respeito dos métodos que ofereçam segurança para diferenciação entre GM. Constatou-se que a análise de pontos característicos individuais na impressão datiloscópicas e plantares, desenvolvimento dental, impressão labial, rugoscopia palatina, medidas faciais antropométricas, biometria ocular e por impressão vocal, padrões de cristas das unhas e de veias, seio frontal e impressão da língua são métodos eficazes para a identificação de GM. Ainda, superando a análise convencional de DNA, surgiu a análise genética por meio das variações sequenciais do genoma, denominado de Massively Parallel Sequencing que tornou possível distinguir gêmeos monozigóticos. Além dos métodos primários de identificação humana que permitem a diferenciação de GM, como a papiloscopia e odontologia, diversos métodos para diferenciação de GM estão descritos na literatura, e cada qual possui suas vantagens e limitações no sentido de propiciar ao perito a melhor informação no sentido de que GM sejam adequadamente diferenciados

A number of limitations can be found in the methods in identifying monozygotic twins (MT) due to genetic influences, facial and environmental similarities, the search for reliable methods to identify genetically identical individuals has become a great importance for Forensic Science. The objective of this work was to conduct a literature review in search of methods that offer attested identification among MT. It was found that the analysis of individual characteristic points in fingerprint and plantar impressions, dental development, lip impression, palatal rugoscopy, anthropometric facial measurements, ocular and voice impression biometry, patterns of nail ridges and veins, sinus Front and tongue print are effective methods for MT identification. Also, surpassing the conventional analysis of DNA, genetic analysis emerged through the sequential variations of the genome, called Massively Parallel Sequencing, which made it possible to distinguish monozygotic twins. In addition to the primary methods of human identification that allow the differentiation of MT, such as papiloscopy and dentistry, several methods for differentiating MT are described in the literature, and each one has its advantages and limitations in the sense of providing the expert with the best information in terms of that GM are properly differentiated

Whole-genome analysis of monozygotic Brazilian twins discordant for type 1 narcolepsy: a case report.

BACKGROUND: Narcolepsy type 1 (NT1) is a rare and chronic neurological disease characterized by sudden sleep attacks, overwhelming daytime drowsiness, and cataplexy. When associated with a sudden loss of muscle tone (cataplexy) narcolepsy is classified as type 1, while the absence of cataplexy indicates type 2. Genetic, degenerative, and immunological hypotheses to explain the pathophysiology of NT1 are still a matter of debate. To contribute to the understanding of NT1 genetic basis, here we describe, for the first time, a whole genome analysis of a monozygotic twin pair discordant for NT1. CASE PRESENTATION: We present the case of a pair of 17-year-old male, monozygotic twins discordant for NT1. The affected twin had Epworth Sleepiness Scale (ESS) of 20 (can range from 0 to 24), cataplexy, hypnagogic hallucinations, polysomnography without abnormalities, multiple sleep latency tests (MSLT) positive for narcolepsy, a mean sleep latency of 3 min, sleep-onset REM periods SOREMPs of 5, presence of allele HLA-DQB1*06:02, and Hypocretin-1 level of zero pg/mL (normal values are > 200 pg/mL). The other twin had no narcolepsy symptoms (ESS of 4), normal polysomnography, MSLT without abnormalities, presence of allele HLA-DQB1*06:02, and Hypocretin-1 level of 396,74 pg/mL. To describe the genetic background for the NT1 discordant manifestations in this case, we present the whole-genome analysis of this monozygotic twin pair. The whole-genome comparison revealed that both twins have identical NT1 pathogenic mutations in known genes, such as HLA-DQB1*06:02:01, HLA-DRB1*11:01:02/*15:03:01. The affected twin has the expected clinical manifestation while the unaffected twin has an unexpected phenotype. The unaffected twin has significantly more frameshift mutations as compared to the affected twin (108 versus 75) and mutations that affect stop codons (61 versus 5 in stop gain, 26 versus 2 in start lost). CONCLUSIONS: The differences observed in frameshift and stop codon mutations in the unaffected twin are consistent with loss-of-function effects and protective alleles, that are almost always associated with loss-of-function rare alleles. Also, overrepresentation analysis of genes containing variants with potential clinical relevance in the unaffected twin shows that most mutations are in genes related to immune regulation function, Golgi apparatus, MHC, and olfactory receptor. These observations support the hypothesis that NT1 has an immunological basis although protective mutations in non-HLA alleles might interfere with the expression of the NT1 phenotype and consequently, with the clinical manifestation of the disease.

Follow-up of young adult monozygotic twins after simultaneous critical coronavirus disease 2019: A case report.

Background: The influence of the host genome on coronavirus disease 2019 (COVID-19) susceptibility and severity is supported by reports on monozygotic (MZ) twins where both were infected simultaneously with similar disease outcomes, including several who died due to the SARS-CoV-2 infection within days apart. However, successive exposures to pathogens throughout life along with other environmental factors make the immune response unique for each individual, even among MZ twins. Case presentation and methods: Here we report a case of a young adult monozygotic twin pair, who caught attention since both presented simultaneously severe COVID-19 with the need for oxygen support despite age and good health conditions. One of the twins, who spent more time hospitalized, reported symptoms of long-COVID even 7 months after infection. Immune cell profile and specific responses to SARS-CoV-2 were evaluated as well as whole exome sequencing. Conclusion: Although the MZ twin brothers shared the same genetic mutations which may be associated with their increased risk of developing severe COVID-19, their clinical progression was different, reinforcing the role of both immune response and genetics in the COVID-19 presentation and course. Besides, post-COVID syndrome was observed in one of them, corroborating an association between the duration of hospitalization and the occurrence of long-COVID symptoms.

Manejo del embarazo gemelar monocoriónico monoamniótico: revisión de la literatura y reporte de caso

A propósito de la presentación de un caso de embarazo gemelar monocoriónico monoamniótico, se revisó la literatura sobre su diagnóstico y manejo mediante búsqueda electrónica en la base de datos de Medline, OVID, Cochrane y PubMed entre los años 1966 y 2019. Las palabras clave utilizadas en la indagación fueron: embarazo, gemelos, monoamniótico, enredamiento de cordones. Existe un riesgo alto de muerte fetal súbita en gemelos monoamnióticos causado por el enredamiento de los cordones umbilicales, por lo que el diagnóstico oportuno de la corionicidad y amnionicidad en el embarazo gemelar mediante ecografía puede dar la pauta para una vigilancia fetal estrecha y mejorar así el resultado obstétrico.

In view of the presentation of a case of monochorionic monoamniotic twin pregnancy, the literature on its diagnosis and management was reviewed by electronic search in the Medline, OVID, Cochrane, and PubMed databases between 1966 and 2019. The key words used in the inquiry were: pregnancy, twins, monoamniotic, cord entanglement. There is a high risk of sudden fetal death in monoamniotic twins caused by entanglement of the umbilical cords, so timely diagnosis of chorionicity and amnionicity in twin pregnancy by ultrasonography may provide guidance for close fetal surveillance and thus improve obstetric outcome.

Phenotypic analysis of discordant monozygotic twins for pain-related temporomandibular joint disorder. Case report / Análise fenotípica de gêmeas monozigóticas discordantes para disfunção temporomandibular dolorosa. Relato de caso

ABSTRACT BACKGROUND AND OBJECTIVES: The design of research with monozygotic twins discordant for the disease has emerged as a powerful tool for the detection of phenotypic risk factors. The aim of this study is to report a clinical case of monozygotic twins discordant for pain-related temporomandibular joint disorder (TMD) from a cognitive-behavioral-emotional phenotypic analysis, from the comparison of clinical variables of pain, history of exposure to painful procedures in early childhood, and coping with pain. CASE REPORT: TMD-Twin presented a diagnosis of painful (myofascial pain with referral) and joint (disk displacement with reduction) TMD according to the criteria of the DC/TMD. Control-Twin did not show TMD, however she presented other chronic pains. TMD-Twin showed reduced pressure pain threshold, hyperalgesia in trigeminal and extra-trigeminal regions compared to the Control-Twin. TMD-Twin was more exposed to painful procedures and emotional events due to congenital heart problems. Both had central sensitization based on the Central Sensitization Inventory, although TMD-Twin had more catastrophic thoughts about pain. TMD-Twin presented an internal locus of control. CONCLUSION: Both monozygotic twins presented a chronic pain phenotype, although they were discordant with the TMD-related pain. The main differences were the lower pressure pain threshold and higher hyperalgesia locally presented by TMD-Twin. The internal locus of control indicates greater pain sensitivity, with better coping of the painful experience for the TMD-Twin. One possible explanation for this clinical condition can be that painful experiences in early childhood have shaped a phenotype of greater sensitivity with better coping and resilience to the painful condition.

RESUMO JUSTIFICATIVA E OBJETIVOS: O desenho da pesquisa com gêmeos monozigóticos discordantes para a doença surgiu como uma ferramenta poderosa para a detecção de fatores de risco fenotípicos. O objetivo deste estudo foi relatar um caso clínico de gêmeas monozigóticas discordantes para disfunção temporomandibular (DTM) dolorosa a partir de análise fenotípica cognitivo-comportamental-emocional entre elas, por meio de comparação de variáveis clínicas de dor, histórico de exposição a procedimentos dolorosos na primeira infância e enfrentamento de dor (autoeficácia e lócus de controle). RELATO DO CASO: A gêmea-DTM apresentou diagnóstico de DTM dolorosa (dor miofascial com referência) e articular (deslocamento do disco com redução) segundo os critérios do Critérios de Diagnóstico para Distúrbios Temporomandibulares. A gêmea--controle não apresentou DTM, contudo apresentou manifestação clínica de outras dores crônicas. A gêmea-DTM apresentou limiar de dor à pressão reduzido, hiperalgesia em regiões trigeminais/extra-trigeminais quando comparados à gêmea-controle, que na primeira infância foi mais exposta a procedimentos dolorosos devido a problemas cardíacos congênitos. Ambas apresentaram sensibilização central de acordo com o Inventário de Sensibilização Central, embora a gêmea-DTM apresentou mais pensamentos catastróficos sobre a dor. A gêmea-DTM apresentou lócus de controle interno. CONCLUSÃO: Ambas as gêmeas apresentaram fenótipo de dor crônica, apesar do fato de serem discordantes para a DTM. Dentre as avaliações, as que mais diferiram entre o par foram o baixo limiar de dor à pressão e hiperalgesia local presentes na gêmea com DTM. O lócus de controle interno associado à maior sensibilidade indicou melhor enfrentamento da experiência dolorosa para a gêmea-DTM. Uma possível explicação para esta manifestação clínica está pautada na hipótese de que experiências dolorosas na primeira infância vivenciadas por ela tenham moldado um fenótipo de maior sensibilidade com melhor enfrentamento e resiliência frente à condição dolorosa.

Association of Vitamin D Supplementation in Cardiorespiratory Fitness and Muscle Strength in Adult Twins: A Randomized Controlled Trial.

Although vitamin D is related to cardiorespiratory fitness and muscle strength, there is no evidence in the literature about the genetic influence of the response to vitamin D supplementation and improvements in these parameters. Therefore, we evaluate the effect of longitudinal supplementation of vitamin D on parameters of physical fitness in monozygotic twins. In total, 74 participants were included, with a mean age of 25 years, divided into two groups, one group received supplementation with cholecalciferol for 60 days and the other group did not. Cardiorespiratory fitness and muscle strength were measured before and after supplementation through maximal treadmill tests and dynamometry, respectively. Wilcoxon tests were used to compare intragroup results and the Mann-Whitney test to examine intergroup differences. There was an increase in the serum concentration of vitamin D in participants who ingested the supplementation. Cardiorespiratory fitness improved after supplementation through increases in the values of maximum oxygen consumption of 28% (p < .001). Muscle strength in left hand grip increased 18% in participants who received the supplement (p = .007). Sixty days of cholecalciferol supplementation improved cardiorespiratory fitness and upper limb muscle strength.

Síndrome de transfusão feto-fetal: revisão de literatura / Twin-twin transfusion syndrome: a literature review

A síndrome de transfusão feto-fetal é uma complicação das gestações gemelares monocoriônicas. Além de ocorrer comumente no segundo trimestre, apresenta elevada morbimortalidade fetal e neonatal, e taxas de incidência que variam de 10 a 15% dentre todas as gravidezes monocoriônicas. O objetivo deste estudo é realizar uma revisão de literatura a partir de levantamento bibliográfico acerca dos principais aspectos epidemiológicos, clínicos e terapêuticos da STFF. A base de dados PubMed foi consultada, uma vez que os termos de pesquisa utilizados foram "síndrome de transfusão feto-fetal", "diagnóstico" e "tratamento". Obtiveram-se sessenta e oito artigos de revisão de literatura e/ou revisão sistemática, sendo que apenas vinte e nove foram selecionados após aplicação dos critérios de elegibilidade. Em relação à fisiopatologia, a síndrome é explicada pela transferência sanguínea direta entre os fetos gemelares através de anastomoses arteriovenosas placentárias, conceitualmente determinando a existência de um feto receptor e outro doador. Embora as gestantes comumente se apresentam assintomáticas, as repercussões clínicas fetais costumam ser graves. O diagnóstico é exclusivamente ultrassonográfico e deve ser feito o mais precocemente possível, ressaltando-se a importância da detecção da corionicidade da gestação gemelar, além de acompanhamento ultrassonográfico seriado para rastreio do desenvolvimento da síndrome. Apesar de ainda não haver protocolo de tratamento bem estabelecido, a ablação dos vasos placentários a laser é tida como o padrão-ouro dentre as opções terapêuticas disponíveis. Apresenta elevada taxa de sobrevida de pelo menos um dos fetos e baixos índices de sequelas neurológicas neonatais, podendo ser realizada somente até a 26ª semana de gestação.

Twin-twin transfusion syndrome is a complication of monochorionic twin pregnancies. In addition to commonly occurring in the second trimester, it has high fetal and neonatal morbidity and mortality and incidence rates ranging from 10 to 15% among all monochorionic pregnancies. This study aims to perform a literature review based on a bibliographic survey about the main epidemiological, clinical and therapeutic aspects of TTTS. The PubMed database was consulted, as the search terms used were "twin-twin transfusion syndrome", "diagnosis", and "treatment". Sixty-eight literature review and systematic review articles were obtained, and only twenty-nine were selected after applying the eligibility criteria. About the pathophysiology, the syndrome is explained by direct blood transfer between the twin fetuses through placental arteriovenous anastomoses, determining the existence of a recipient fetus and another donor. Although pregnant women are usually asymptomatic, the clinical fetal repercussions are often severe. Diagnosis is exclusively ultrasonographic and must be made as early as possible, emphasizing the importance of detecting chorionicity in twin pregnancy, in addition to serial ultrasonographic follow-up to track the development of the syndrome. Although there is still no well-established treatment protocol, endoscopic laser ablation of vascular anastomoses is considered the gold standard among the available therapeutic options. It has a high survival rate for at least one of the fetuses and low rates of neonatal neurological sequelae and can only be performed until the 26th week of pregnancy.

Safety of neuraxial anesthesia in patients twin pregnancy and twin-to-twin transfusion syndrome taken to laser photocoagulation. Retrospective cohort study / Seguridad de la anestesia neuroaxial en mujeres con embarazo gemelar y síndrome de transfusión feto-fetal, sometidas a fotocoagulación láser. Estudio de cohorte retrospectiva

Objective: To describe the clinical characteristics and the frequency of maternal, fetal and neonatal complications in accordance with the neuraxial anesthesia (NA) technique in women with twin-totwin transfusion syndrome (TTTS) treated with laser photocoagulation. Materials and Methods: Descriptive retrospective cohort study of pregnant patients with TTTS treated with laser photocoagulation under NA at Fundación Valle del Lili, Cali (Colombia), between 2013-2017. Patients with Quintero stage V TTTS were excluded. The protocol was approved by the institutional ethics committee. Results: Of the participants, 32 met the inclusion and exclusion criteria. The study population consisted of young, multiparous women. Urgent interventions were performed in 87.5% of cases; 43.7% were Quintero stage III and epidural anesthesia was used in 56.2% of the women. Maternal hemodynamic variables were similar, in accordance with the timing of surgery and the neuraxial technique used. Sustained hypotension occurred in 65.6% of the pregnant women and 9.3% developed pulmonary edema. Pre-term delivery occurred in 65.6% of the patients and 18.7% had premature rupture of membranes. There were 14 fetal demises and five neonatal deaths. There were no cases of maternal mortality. Conclusions: In patients with TTTS requiring laser photocoagulation, the use of epidural, spinal or combined anesthesia is likely associated with similar maternal hemodynamic variables at the time of surgery. Practitioners providing care to these pregnant women must be aware of the frequent occurrence of maternal, fetal and neonatal complications. Prospective studies to assess the safety and effectiveness of the different neuraxial anesthesia techniques in patients with TTTS are required.

Objetivo: describir las características clínicas y la frecuencia de complicaciones maternas, fetales y neonatales, según técnica de anestesia neuroaxial (AN) en mujeres con síndrome de transfusión feto-fetal (STFF) tratadas con fotocoagulación láser (FL). Materiales y métodos: estudio de cohorte retrospectiva descriptivo. Se incluyeron gestantes con STFF tratadas con FL y AN en la Fundación Valle del Lili, Cali (Colombia) entre 2013-2017. Se excluyeron pacientes con STFF estadio-V de Quintero. Se usó estadística descriptiva. El protocolo fue aprobado por el Comité de Ética de la institución. Resultados: 32 participantes cumplieron con los criterios de inclusión y de exclusión. La población estuvo constituida por mujeres jóvenes, multíparas. En el 87,5% de los casos se realizó intervención de urgencia. El 43,7% presentaba el estadio-III de Quintero y en el 56,2 % de las gestantes se utilizó anestesia epidural. Las variables hemodinámicas maternas exhibieron un comportamiento similar, acorde al momento de la cirugía y la técnica neuoraxial implementada. El 65,6 % de las gestantes presentó hipotensión sostenida y el 9,3 % desarrolló edema pulmonar. El 65,6 % de las pacientes experimentó parto pretérmino y el 18,7 % ruptura prematura de membranas. Se registraron 14 muertes fetales y cinco neonatales. No se registraron casos de mortalidad materna. Conclusiones: en pacientes con STFF que requieren FL, el uso de la anestesia epidural, espinal o combinada probablemente se asocia con un comportamiento similar al de las variables hemodinámicas maternas, durante los momentos de la cirugía. Los profesionales que brindan atención a estas gestantes deben estar alerta ante la frecuente aparición de complicaciones maternas, fetales y neonatales. Se requieren estudios prospectivos que evalúen la seguridad y la efectividad de las diferentes técnicas de anestesia neuroaxial en pacientes con STFF.

Concordance of Congenital Heart Defect in Monozygotic Twins in Brazil

Abstract Tetralogy of Fallot (TOF) consists of four cardiac changes: interventricular communication, pulmonary stenosis, aortic dextroposition and right ventricular hypertrophy. The prevalence is 0.1 per 1,000 live births. A primiparous mother with gestational age of 38 weeks came to the emergency. At the time, it was verified in her twin pregnancy that one fetus had TOF, thus a pregnancy interruption was scheduled for the following day. In the neonatal physical examination of both, localized acrocyanosis, regular heart rhythm with the presence of a heart murmur, and good peripheral perfusion were found. The echocardiogram of twin 1 revealed: patent foramen ovale; a wide perimembranous interventricular communication of misalignment, with the aorta riding the septum by 50%; hypertrophied and long infundibulum with pulmonary infundibulo-valvular stenosis, with a maximum systolic gradient of 66 mm Hg; both pulmonary arteries presented dimensions of 0.35 mm; pulmonary valve annulus: 0.56 mm; and patent ductus arteriosus measuring 0.19 mm. The echocardiogram of twin 2 showed: patent foramen ovale; a wide perimembranous interventricular communication of misalignment, with the aorta riding the septum by 50%; hypertrophied infundibulum with stenosis pulmonary infundibulo-valve, with a maximum systolic gradient of 33 mm Hg; reduced confluent pulmonary arteries; right pulmonary artery measuring 0.40 mm and left pulmonary artery measuring 0.55 mm; pulmonary valve annulus measuring 0.72 mm; a closed arterial canal, and mild aortic regurgitation. Tetralogy of Fallot is a multifaceted syndrome with a high prevalence in pediatrics. This case is the first case of congenital heart defect concordance for TOF in monozygotic twins in Brazil.

Seguridad de la anestesia neuroaxial en mujeres con embarazo gemelar y síndrome de transfusión feto-fetal, sometidas a fotocoagulación láser. Estudio de cohorte retrospectiva / Safety of neuraxial anesthesia in patients twin pregnancy and twin-to-twin transfusion syndrome taken to laser photocoagulation. Retrospective cohort study

Objetivo: describir las características clínicas y la frecuencia de complicaciones maternas, fetales y neonatales, según técnica de anestesia neuroaxial (AN) en mujeres con síndrome de transfusión feto-fetal (STFF) tratadas con fotocoagulación láser (FL). Materiales y métodos: estudio de cohorte retrospectiva descriptivo. Se incluyeron gestantes con STFF tratadas con FL y AN en la Fundación Valle del Lili, Cali (Colombia) entre 2013-2017. Se excluyeron pacientes con STFF estadio-V de Quintero. Se usó estadística descriptiva. El protocolo fue aprobado por el Comité de Ética de la institución. Resultados: 32 participantes cumplieron con los criterios de inclusión y de exclusión. La población estuvo constituida por mujeres jóvenes, multíparas. En el 87,5% de los casos se realizó intervención de urgencia. El 43,7% presentaba el estadio-III de Quintero y en el 56,2 % de las gestantes se utilizó anestesia epidural. Las variables hemodinámicas maternas exhibieron un comportamiento similar, acorde al momento de la cirugía y la técnica neuoraxial implementada. El 65,6 % de las gestantes presentó hipotensión sostenida y el 9,3 % desarrolló edema pulmonar. El 65,6 % de las pacientes experimentó parto pretérmino y el 18,7 % ruptura prematura de membranas. Se registraron 14 muertes fetales y cinco neonatales. No se registraron casos de mortalidad materna. Conclusiones: en pacientes con STFF que requieren FL, el uso de la anestesia epidural, espinal o combinada probablemente se asocia con un comportamiento similar al de las variables hemodinámicas maternas, durante los momentos de la cirugía. Los profesionales que brindan atención a estas gestantes deben estar alerta ante la frecuente aparición de complicaciones maternas, fetales y neonatales. Se requieren estudios prospectivos que evalúen la seguridad y la efectividad de las diferentes técnicas de anestesia neuroaxial en pacientes con STFF.

Objective: To describe the clinical characteristics and the frequency of maternal, fetal and neonatal complications in accordance with the neuraxial anesthesia (NA) technique in women with twin-to- twin transfusion syndrome (TTTS) treated with laser photocoagulation. Materials and Methods: Descriptive retrospective cohort study of pregnant patients with TTTS treated with laser photocoagulation under NA at Fundación Valle del Lili, Cali (Colombia), between 2013-2017. Patients with Quintero stage VTTTS were excluded. The protocol was approved by the institutional ethics committee. Results: Of the participants, 32 met the inclusion and exclusion criteria. The study population consisted of young, multiparous women. Urgent interventions were performed in 87.5% of cases; 43.7% were Quintero stage III and epidural anesthesia was used in 56.2% of the women. Maternal hemodynamic variables were similar, in accordance with the timing of surgery and the neuraxial technique used. Sustained hypotension occurred in 65.6% of the pregnant women and 9.3% developed pulmonary edema. Pre-term delivery occurred in 65.6% of the patients and 18.7% had premature rupture of membranes. There were 14 fetal demises and five neonatal deaths. There were no cases of maternal mortality. Conclusions: In patients with TTTS requiring laser photocoagulation, the use of epidural, spinal or combined anesthesia is likely associated with similar maternal hemodynamic variables at the time of surgery. Practitioners providing care to these pregnant women must be aware of the frequent occurrence of maternal, fetal and neonatal complications. Prospective studies to assess the safety and effectiveness of the different neuraxial anesthesia techniques in patients with TTTS are required.

Monozygotic dichorionic-diamniotic twin pregnancy after single embryo transfer at blastocyst stage: a case report.

Single embryo transfer is highly encouraged on in vitro fertilization due to its lower rates of multiple pregnancy. Nevertheless, the likelihood of multiple pregnancy is higher when using assisted reproductive technology, probably because of embryo handling. Timing is crucial in the post-fertilization division of a single embryo to establish the amniocity and chorionicity of the gestation. In the case reported a 38 year-old woman, nulligravid, had a single blastocyst implanted, which resulted in monozygotic dichorionic-diamniotic twins. Despite being rare, there are reports of similar cases questioning the current knowledge on time of embryo division and the impact of assisted reproduction.