Twin reversed arterial perfusion syndrome in a monochorionic monoamniotic twin pregnancy.

OBJECTIVE: Twin-Reversed Arterial Perfusion (TRAP) sequence is a rare complication of monochorionic multiple gestation. Conservative management should be considered if there is no poor prognostic factor. CASE REPORT: This is a 35 year-old female with twin pregnancy with acardiac monster. Under the request of the patient, there was no intervention during the whole pregnancy. We keep regular and close sonography weekly follow up. There was no maternal complication and there was also no heart failure sign or polyhydramnios of the donor twin. Minimal blood flow was noted at the anastomotic vessels under the sonography at late gestational age. Due to breech presentation, cesarean section was performed at gestational age 37 + 1/7 weeks. She delivers a healthy baby smoothly. CONCLUSION: Antenatal sonography is an important tool to evaluate the fetus status. Under special condition, term pregnancy is still possible without any treatment. CASE REPORT: Twin reversed arterial perfusion syndrome in a monochorionic monoamniotic twin pregnancy.

Partial duplication of head--a rare congenital anomaly.

Duplication of notochord results in rare congenital anomalies like double headed monsters, with or without trunk/limb duplication, depending upon the extent of notochordal abnormality. Here we describe the morphological abnormalities in a case of partial duplication of cranial structures with fusion of the two. Autopsy findings suggest that the bifurcation of the neural tube took place around 4th to 6th week of gestation. There are only few reports in English literature describing the autopsy findings of such an anomaly, which is termed as Diprosopus triophthalmus in the modern literature.

Syndromology: an updated conceptual overview. VIII. Deformations and disruptions.

A deformation is an abnormal form or position of the body caused by nondisruptive mechanical forces. Clubfoot, congenital hip dislocation, and infantile mandibular asymmetry (not based on mandibular malformation) serve as examples. The musculoskeletal system is involved in almost all deformations. Various disturbances of intrauterine movement are the usual causes and commonly occur during the fetal period. Causes may be mechanical or malformational. The former includes first pregnancies, small maternal size, uterine malformations and tumors, and amnionic rupture leading to oligohydramnios. Malformational causes usually involve the urogenital system and the central nervous system. A disruption is a morphologic defect of an organ, part of an organ, or a larger region of the body resulting from a breakdown of, or interference with, an originally normal developmental process. Amnionic band disruptions with digital amputations serve as an example. The most recent studies of disruptions and their suggested mechanisms are discussed. Finally, the interrelationships between malformations, deformations, and disruptions are explained.

Epigastrius with omphalocele--report of a case.

An epigastrius (parasitic twinning in the epigastrium) was delivered via the vaginal route spontaneously and died 37 days later. The autosite had cardiac hypertrophy with VSD, PDA, and PFO and an omphalocele. The liver was partly conjoined. There was a small swelling at the lower part of the autosite's bifurcated sternum to which the parasitic left pelvis and lower extremity were attached. On the second day after birth, parasitectomy was performed. The amputated specimens consisted of a small left pelvic girdle with a free extremity, a scrotal mass, nipplelike structures and two small protuberances externally. The liver, intestines, two testes, one kidney, one ureter, and the bladder were contained within the omphalocele. Although all of the organs and external structures of the parasite had abnormal histopathological findings, differentiated muscle fibers and submucous and/or myenteric plexus were observed.

[The fetus without a heart: the diagnosis and observations using ultrasound. A case history]. / Le foetus acardiaque: diagnostic et surveillance échographique. A propos d'un cas.

The condition is extremely rare, since acardia is only found in 1% of monozygotic twin pregnancies. A case was discovered and observed using ultrasound and was then studied anatomically and pathologically. The histopathology and the physiopathology of the malformation is described. The aetiology that has been most usually accepted is that there is an anastomosis between the two umbilical cords of the two "twins" and that this leads to an inversion of the direction of the circulation in the affected fetus. The failure of the myocardium to develop would follow this vascular abnormality because of failure of the allantoid vessels to fuse. The interest in this kind of observation lies in the possibility of making the diagnosis very early in pregnancy using ultrasound, and of following the evolution and the regression of the acardiac fetus throughout the pregnancy, and with the possibility of comparing the views obtained by ultrasound with the anatomo-pathological features that can be diagnosed after birth.

[Morphologic characteristics of successive transformations of mouse blastocysts into teratoids during development under the testicular capsule]. / Morfologicheskaia kharakteristika posledovatel'nykh preobrazovanii blastotsist myshei v teratoidy pri ikh razvitii pod kapsuloi semennika.

Blastocysts of the CBAXC57Bl mouse strain transplanted under the testicular albuminous membrane normally develop (but delay in time) during 7-9 days forming embryos at the stage of the deep neural groove. The data obtained demonstrate that there is a definite autonomy in the development of early embryos not depending on any influence from the uterus at this stage. Desorganization of the embryo occurs 9-11 days after transplantation of the blastocyst. Further (14-20 days after transplantation) as a result of active histogenesis and atypical organogenesis, immature teratoid is forming. Secondary giant cells of the trophoblast develop in the presence of the internal cellular mass derivatives.

Determining role of the optic vesicle in orbital and periocular development and placement.

Nine patients with aberrations in development and placement of the eyes and periocular structures who also had serious defects in central nervous system development were evaluated in order to better understand normal ocular development. Included were an incompletely developed twin stillborn infant who lacked both eyes and the nose, a stillborn infant with cyclopia hypognathia, 6 spontaneous abortuses with varying degrees of holoprosencephaly, and a 17-year-old male with a serious defect in central nervous system development whose right eye was positioned laterally above the right ear. In all cases, evidence indicates that orbital and periocular structures are determined by the underlying optic vesicle rather than independently derived as has been suggested by previous studies.

[Teratoid formation after implanting early embryos]. / Formirovanie teratoidov pri implantatsii rannikh zarodyshei.

The ability of embryos of different age to form teratoids upon their transplantation under the renal capsule was studied in the CBA mice. The teratoids were shown to form most actively upon transplantation of 10 days old embryos; 7 days old embryos, besides teratoids, may give origin to rapidly growing teratomas. The number of differentiated tissues in teratoids increases with the age of transplanted embryo.

The acardiac anomaly.

Karyotype analysis of a premature human acardiac twin disclosed normal chromosomes. A review of previous cytogenetic, placental and animal studies suggests that chromosomal errors are not the cause of the acardiac anomaly. Rather, they point to the placental vascular anastomoses as the principal pathogenetic event.

Blood vessels of the twin placenta in relation to zygosity.

The anatomical characteristics of the arteries, veins and arteriovenous relationships, velamentous vessels, and vascular communications in 148 placentae from multiple pregnancies were studied. All features were found to show discordance of varying degrees, irrespective of the twins' zygosity. Singular involvement of one component of the twin placenta by hydramnios or congenital defects, incidence of vascular communications and the anatomical characteristics of the vessels in conjoined twins, acardiac monsters and triplets, and a chromosomal discordance in a MZ pair, lend additional support to the initial surmise of anatomical characteristics of fetal blood vessels of the placenta being determined by functional demands. It is suggested that the inequalities of prenatal environment be assessed by an examination of the fetal blood vessels of the placenta before drawing homologies in the twin concordance studies.

Biology of the twinning phenomenon: embryogenesis and teratogenesis.

The twinning phenomenon has always interested the great public, the artists, and naturally the scientists. Isidore Geoffroy St. Hilaire has established a classification still now valid. This classification considers the different types of double monsters which are found in nature in all classes of vertebrates, including man. To explain the twinning phenomenon, the experimental realizations have progressed by successive bounds after the preliminary attempts of different authors. Now, when it is question of experimental duplication, anybody thinks of Speman for the amphibians, of Lutz for the birds, of Seidel for the rabbit, and of Tarkowsky for the mouse. Now, it is possible to conceive a twinning resulting from the separation of the first blastomeres (amphibian, rabbit, mouse) and a twinning originating from the fissuration of the blastoderm (bird, mammal). All these experiments confirm the unicist-theory. If a total or partial regulation of the excedents may be experimentally realized, no argument can however support this theory in the realization of the double monstrosity.

Extroversion of cerebral hemispheres in a full term human foetus.

Extroversion of the cerebral hemispheres and a posterior intestinal fistula are described in a male foetus with single umbilical artery and craniorhachischisis. The paper has distinction of describing for the first time the cerebral extroversion in a full term human foetus. At this stage of development, the everted cerebral hemispheres, after having proliferated exuberantly to a considerable size present a disorganised appearance which would vary in every case of this type. However, the lateral ventricles are still visible, structures comparable to thalami and choroid plexus can be made out and the vascular masses with large blood clots seen in anencephaly are minimal. That the posterior intestinal fistula represents persistence of an accessory neurenteric canal is discussed. The neural and neurenteric defects in the specimen described here are possibly due to abnormal arterial pattern in the caudal half of the body, imposed by single umbilical artery.

Evidence for normal cum accessory neurenteric canals in a human fetus.

Multiple anomalies, including a vertebral cleft in the cervicothoracic region containing the posterior pharyngeal diverticulum, and duplication of the lower lumbar spine with absence of sacrum and coccyx, are described in a stillborn anencephalic female monster. It is postulated that vertebral division at two levels is evidence of two neurenteric canals, a caudal normal canal and a cranial accessory one. This supports the 'accessory neurenteric canal' theory for vertebral divisions in the cervicothoracic regions. Other associated defects, such as exomphalos, ectopia vesicae and craniorhachischisis, are correlated with the presence of a single umbilical artery.

Cranial neural crest extirpation and cyclopian development.

Extirpation of cranial neural crest cells in presomite to 5 somite chick embryos produces monsters which in all essential respects are identical to human cyclopias. The primary lesion involves damage to the forebrain and consequently the inhibition of the nasal placode and nasal organ development as well as the destruction of the anterior neural crest cells, with the resultant absence of the nasal and interobital septa and of the facial dermal skeleton.