Fetal disruptions: assessment of frequency, heterogeneity, and embryologic mechanisms in a population referred to a community-based stillbirth assessment program

Conservative Management of an Unusual Congenital Abdominal Wall Defect: A Case Report

Congenital abdominal wall defects comprise a spectrum of anatomical anomalies of the abdominal wall. Most of these anomalies are located in the midline. However, in rare cases, it was lateral and usually found to be a fascial defect with intact skin coverage. We report an unusual case of lateral musculocutaneous abdominal wall defect in a full-term baby boy. The defect is not classified under any of the well-known abdominal wall anomalies. Non-operative management achieved excellent and satisfactory results. Conservative management should always be considered whenever applicable, as it is safe and cost effective.

Extended reality visualization of medical museum specimens: Online presentation of conjoined twins curated by Dr. Jacob Henle between 1844-1852

Background

The purpose of this study is to characterize a full-term conjoined twins' cadaver curated by Dr. Jacob Henle sometime between 1844 and 1852 and demonstrate digital distribution of an old and rare medical museum specimen using an extended reality (XR) model workflow.

Methods

The cadaver (Preparation 296) is in the Department of Anatomy and Cell Biology at the University of Heidelberg. An XR display workflow comprises image capture, segmentation, and visualization using CT/MR scans derived from the cadaver. Online radiology presentation to medical students focuses on diagnostic characteristics of anatomical systems depicted with XR models.

Results

Developmental defects in Preparation 296 include duplicated supradiaphragmatic structures and abnormal osteological features. Subdiaphragmatically, the gut is continuous on the right, but terminates at the distal esophagus on the left. One large liver occupies the abdomen with one spleen located on the left side. Observations suggest duplication of the primitive streak and separate notochords rostrally. Duplication occurs near the yolk sac and involves midgut formation while secondary midline fusion of the upper extremities and ribs likely results from the proximity of the embryos during development. Medical students access the model with device agnostic software during the curricular topic "Human Body Plan" that includes embryology concepts covering mechanisms of twinning.

Conclusions

The workflow enables ease-of-access XR visualizations of an old and rare museum specimen. This study also demonstrates digital distribution and utilization of XR models applicable to embryology education.

Tessier's Cleft Number 6 Revisited: A Series of 26 new Cases and Literature Review of 44

OBJECTIVE

To fix a gray zone left in Tessier's classification of rare clefts with cleft 6 and to give a more comprehensive description of cleft 6 anatomy.

DESIGN

The material used for the research was a series of 26 clinical cases of patients with assessed cleft 6 and 44 cases found out of a literature review with enough data to be useful. The 70 cases were cross-examined by the authors.

STUDY SETTING

The authors are senior craniofacial surgeons working in high-case load department from university centers where the patients are documented and receive primary as well as secondary treatment and follow-up.

PATIENTS

The patients were selected out of the series of craniofacial deformities taken care of by the authors' department as rare clefts.

MAIN OUTCOME

We describe the full spectrum of cleft 6 as an autonomous entity that could present itself in three subtypes: 6a is the most proximal and could be associated with cleft 8. The subtype 6b is medial toward the zygomatic arch and frequently associated with a bone and teeth appendage (frequently described as a "maxillary duplication"). The subtype 6C goes toward the external ear between the helix crus and the auditory meatus.

CONCLUSIONS

The Tessier's opinion is that Treacher Collins syndrome was the association of clefts 6, 7, and 8 and is no longer sustainable in the light of modern genetics. Most of the cleft 6 are misdiagnosed in the literature.

3137 fetuses in 33 years: What we have learned from the Wisconsin stillbirth service program

The Wisconsin Stillbirth Service Program (WiSSP) provided expert review by a dysmorphologist for community-acquired data on 3137 fetal deaths between 1983 and 2017. Intrinsic fetal causes were consistently identified in about 25% while placental and maternal causes were recognized with increasing frequency as attention was shifted from a primarily fetal to a multifocal approach. Identification of causes increased from 40% to 78% and in about half of cases results of the review altered recurrence risk and/or future pregnancy management. Banked data from WiSSP formed the basis of 24 publications, more than half of which have a genetic counselor and/or summer premedical student intern as an author. The earlier publications emphasized validation of the concept of community-based evaluation with central review, the utility of various parts of the WiSSP protocol, the similarity of second-trimester miscarriages <20 weeks to later stillbirths with respect to causes identified and recurrence risks, and the potential for results of etiologic evaluation to influence future prenatal care. The most important recurrent theme, however, was the interaction of intrinsic fetal, placental, and maternal factors in contributing to fetal demise. This implies that, at least in developed nations with available obstetric care, reduction in stillbirth will require careful attention to the myriad of factors contributing to fetal, placental, and maternal well-being.

Body stalk anomalies in pig-Definition and classification

The presence of body wall closing defects (abdominoschisis and thoracoabdominoschisis) in combination with other congenital malformations was studied in the pig (Sus scrofa domesticus). After clinical examination and literature review, body wall defects with multiple congenital anomalies in eight pigs were described, and classified using anatomical and embryological criteria. Several BSA presentations were identified and classified as follows: (a) BSA Type I: fetus with spinal and UC defects, thoracoabdominoschisis, anal atresia and/or other internal organs structural defects, and structural limb defects; (b) BSA Type II: fetus with spinal and UC defects, thoracoabdominoschisis, anal atresia and/or other internal organs structural defects, and nonstructural limb defects; (c) BSA Type III: fetus with spinal and UC defects, abdominoschisis, anal atresia and/or other internal organs structural defects, and structural limb defects; and (d) BSA Type IV: fetus with spinal and UC defects, abdominoschisis, anal atresia and/or other internal organs structural defects, and nonstructural limb defects. Two types of LBWC were differentiated: LBWC Type I: characterized by thoracoabdominoschisis and structural limb defects, and LBWC Type II: characterized by abdominoschisis and structural limb defects, corresponding to BSA type I and type III. This is the first report on BSA and LBWC in the pig.

The prevalence of amnion rupture sequence, limb body wall defects and body wall defects in Alberta 1980-2012 with a review of risk factors and familial cases

Prevalence rates of amnion rupture sequence, limb body wall defect, and body wall defects vary widely. Comparisons are difficult due to small case numbers and the lack of agreement of definition, classification, and pathogenesis. This study reports the prevalence of cases classified in five distinct categories. The Alberta Congenital Anomalies Surveillance System data on live births, stillbirths, and terminations of pregnancy (<20 weeks gestation) occurring between 1980 through 2012 with the ICD-10 Royal College of Paediatrics and Child Health Adaptation codes used for congenital constriction bands (Q79.80) and body wall complex (Q89.7) were reviewed. During the 33-year-study period, there were 153 eligible cases ascertained from 1,411,652 live births and stillbirths, giving a prevalence of 1.08/10,000 total births. There were more males (52%) than females (45%) and 3% were of unknown sex. The average maternal age, birth weight, and gestation was 27 years, 2,701 g, and 35 weeks, respectively. Limb deficiencies occurred in 78% of cases. Amniotic bands with limb deficiency was the most common phenotype (48%). Digital limb deficiency was the most frequent type (56%); however, cases with body wall defects had more severe types of limb deficiencies. The upper limbs only were affected more times (44%), and there was no side preference. Most cases are sporadic but a number of familial occurrences have been reported although some have insufficient documentation and others misdiagnosed. A review of putative risk factors gives conflicting results. © 2016 Wiley Periodicals, Inc.

Role of Ultrasound in Body Stalk Anomaly and Amniotic Band Syndrome

Body stalk anomaly (BSA) and amniotic band syndrome (ABS) are rare similar fetal sporadic polymalformative syndromes of unknown etiology, though there are certain differences between them. BSA is a combination of developmental abnormalities involving neural tube, body wall, and the limbs with persistent extra embryonic coelomic cavity. ABS is characterized by the presence of thin membrane-like strands attached to fetal body parts and causing constrictions and amputations. This is a cohort study involving 32,100 patients who were referred for routine antenatal ultrasound scan. The data was entered prospectively into a computer database. The duration of study was 3 years. In our study, ultrasound examination in 86 patients demonstrated ventral wall defects, craniofacial defects, and spinal and limb deformities as isolated or combined abnormalities. In those, 10 patients were suspected/diagnosed as BSA/ABS including a twin of a dichorionic diamniotic gestation. The typical features of body stalk anomaly can be detected by ultrasound by the end of the first trimester, which is important for the patient counselling and management. We are presenting these rare conditions and highlighting the importance of early sonographic imaging in diagnosing and differentiating them from other anterior abdominal wall defects.

Congenital lateral abdominal wall hernia

Congenital abdominal wall defects that are located outside of the anterior wall are extremely rare and difficult to classify because there are no well accepted guidelines. There are two regions outside of the anterior wall: the flank or lateral wall; and the lumbar region. We report the case of a patient with an oval 3 cm-diameter hernia defect located above the anterior axillary line, which affects all layers of the muscular wall. An anorectal malformation consisting of a recto-vestibular fistula was also identified, and chest X-ray showed dextrocardia. The suggested treatment is repair of the defect before 1 year of age. Given that the anomalies described may accompany lateral abdominal wall hernia, it is important to diagnose and treat the associated defects.

Prenatal MRI evaluation of limb-body wall complex

BACKGROUND

The sonographic (US) features of limb-body wall complex have been well documented; however the literature regarding the findings on MRI in limb-body wall complex is scant.

OBJECTIVE

To characterize the prenatal MRI features of limb-body wall complex.

MATERIALS AND METHODS

We performed a retrospective review of all MRI scans of fetuses diagnosed with limb-body wall complex at our institution from 2001 to 2011. Fetuses without correlating US scans or follow-up information were excluded. Three pediatric radiologists blinded to the specific US findings reviewed the prenatal MRIs. Images were evaluated for the organ location and attachment, the body part affected, characterization of the body wall defect, and spinal, limb and umbilical cord abnormalities.

RESULTS

Ten subjects met inclusion criteria. MRI was able to detect and characterize the body part affected and associated abnormalities. All fetuses had ventral wall defects, a small thorax and herniated liver and bowel. The kidneys were extracorporeal in three cases. The extruded organs were attached to the placenta or the uterine wall in all cases. Abnormal spinal curvatures of various degrees of severity were present in all cases. Eight cases had a short, uncoiled cord. Limb anomalies were present in 6 of the 10 cases.

CONCLUSION

We illustrate the common fetal MRI findings of limb-body wall complex. The prenatal diagnosis of limb-body wall complex and the differentiation of this defect from treatable abdominal wall defects are crucial to providing appropriate guidance for patient counseling and management.

Limb-body wall defect. Is there a defensible hypothesis and can it explain all the associated anomalies?

Aside from gastroschisis and omphalocele, major defects of the ventral body (thoracoabdominal) wall are relatively uncommon and almost universally lethal. They are most often associated with other anomalies including those of the limbs that may range from amelia to mild positional deformations, unusual craniofacial malformations, and a variety of visceral abnormalities that include the heart, lungs, genitourinary system, and gut. This complex of ventral wall anomalies has been discussed under a broad and changing nomenclature that has included amniotic band disruption complex, amnion rupture sequence, limb-body wall defect (or complex), and simply body wall complex. Three major theories have been suggested to explain this complex: early amnion rupture (operating through uterine pressure and/or disruption by amniotic bands), vascular compromise (primarily hypoperfusion), and an early intrinsic defect of the developing embryo. We present four patients that illustrate the spectrum of ventral body wall defects, and from there critique the current hypotheses of pathogenesis. We conclude that this association of malformations originates as early as the embryonic disc stage, and that some of the observed associated anomalies are secondary complications of the primary disturbance in embryogenesis. We propose a new explanation for the atypical facial clefts and cranial malformations that are often observed.

Two major patterns of nongenetic malformations are found at autopsy

Patterns of malformations seen in autopsies may contribute to the understanding of their pathogenetic mechanisms. Two entities, acardiac twins (ATs) and amniotic band disruption complex (ABDC), have distinct patterns, indicating different mechanisms, namely vascular perfusion deficit and external disruption. With ATs and ABDC as model groups, this study was undertaken to see if other dysmorphic infants with the characteristic defects of these models formed distinct and numerically important groups. A total of 192 autopsies with nongenetic malformations was divided into groups including (1) those with defects found in the ATs but not in the ABDC, (2) those with defects found only in the ABDC, and (3) those with a mixture of exclusive defects from each model group. The cases followed the characteristic defects of ATs or ABDC in 20% (group 1) and 28% (group 2), respectively, forming 2 large and distinct groups; only 4% had mixed malformations (group 3). Group 1 had different characteristics from group 2 as a result of the frequent multiple malformations, often with congenital heart defects (CHDs), internal and inferior malformations. These cases were probably related to a vascular perfusion deficit. Group 2 had a majority of females and single, external, and superior defects, but it lacked CHDs and inferior malformations. These cases were likely due to external disruption. Two large and distinct groups of autopsies with nongenetic malformations were thus identified, and their mechanisms are proposed to be similar to those of the model groups.

Amniotic band syndrome and/or limb body wall complex: split or lump

Six cases of amniotic band syndrome/limb body wall complex were studied in respect to clinicopathologic characteristics. The diagnosis was based on two out of three of the following manifestations: cranio facial clefts; limb body wall defects and amniotic band attachment. Four cases were stillborn and associated with internal defects, including central nervous system. Two cases had facial and limb defects and were live born (3-5 years old at examination). Phenotypic features of the stillborn cases were craniofacial clefting, thoracoabdominoschisis, amputation, ring constriction, amniotic band adhesion, placental adhesions, and internal malformations. Histology of bands revealed fibroconnective tissue as well as flattened epithelial cells together with neuroectodermal elements. Umbilical cord section revealed an abnormal number of vessels. When analyzing the observed data in relation to their etiology, it was found that amniotic disruption, vascular disruption or genetic disruption could explain the amniotic band syndrome/limb body wall complexes, alone or in combinations. A brief review of literature in search of pathogenesis is offered along with an etiopathogenetic model.

Prenatal ultrasonographical features of limb body wall complex: a review of etiopathogenesis and a new classification

Limb body wall complex is a spectrum of multiple severe anomalies. The etiopathogenesis and clinical classification are still under discussion. In our article, while reviewing previous etiopathogenetical hypothesis, we propose a new clinical classification regarding embryological theories and pheneotypical features. According to the Van Allen diagnostic criteria, the findings of 6 affected fetuses are presented. Prenatal diagnosis was performed in 5 of 6 cases. Craniofacial malformations were present in only 1 case. Thoracic defect and abdominoschisis (either infraumbilical or supraumbilical) associated with visceral eventration, placental-umbilical cord anomalies, and limb defects were detected in the other 5 cases. Aberrant development of each of the 4 embryonic folds (cephalic, 2 lateral abdominal, and caudal) associated with faulty umbilical ring development and placental formation were considered responsible for development of various malformations. In previous clinical classifications, existence or absence of the craniofacial malformation was utilized as an unique discriminating criterion while multiple anomalies exist. In this report, we propose a new clinical classification concerning almost all anomalies caused by defective placental attachment and maldevelopment of the 4 folds.

Finally, a sense of closure? Animal models of human ventral body wall defects

Malformations concerning the ventral body wall constitute one of the leading categories of human birth defects and are present in about one out of every 2000 live births. Although the occurrence of these defects is relatively common, few detailed experimental studies exist on the development and closure of the ventral body wall in mouse and human. This field is further complicated by the array of theories on the pathogenesis of body wall defects and the likelihood that there is no single cause for these abnormalities. In this review, we summarize what is known concerning the mechanisms of normal ventral body wall closure in humans and mice. We then outline the theories that have been proposed concerning human body wall closure abnormalities and examine the growing number of mouse mutations that impact normal ventral body wall closure. Finally, we speculate how studies in animal models such as mouse and Drosophila are beginning to provide a much-needed mechanistic framework with which to identify and characterize the genes and tissues required for this vital aspect of human embryogenesis.

Unusual congenital abdominal wall defect and review

Abdominal wall defects distant from the umbilicus are very unusual. We describe a patient with a congenital defect adjacent and external to the lateral border of the recti muscles, rounded in shape, bilateral and symmetrical, but affecting different structures in each side, musculocutaneous agenesis in the left side and only muscle agenesis in the right one. The morphologic characteristics of the defect and the absence of associated anomalies, suggest that this anomaly may be the result of an event acting during phenogenesis. We consider that this defect is different from other structural abnormalities of the anterior abdominal wall which occur much earlier at certain periods of the embryogenesis. Though the etiology is speculative, we could postulate a disruptive origin of the defect of unknown cause.

The origin of monozygotic twinning

The incidence of monozygotic twinning appears to be increasing within the field of assisted human reproduction. Many theories have been put forward as to how and when this occurs. Whatever the cause, the normal events of embryo development, which necessarily involve axis formation, patterning and polarization, need to be adhered to in order to obtain a viable offspring. This paper describes the course of development in terms of axis formation and polarity and offers suggestions as to how either a disruption of this or duplication events in the course of the formation of these parameters could prevent or contribute to a twinning event. The likelihood of twinning occurring at any point is discussed in terms of the establishment of polarity and axes.

Limb-body wall complex: 4 new cases illustrating the importance of examining placenta and umbilical cord

Limb-body wall complex (LBWC) is a rare, sporadic, congenital defect defined as a combination of at least two of three characteristics: 1. limb defects, 2. anterior body wall defects, and 3. exencephaly or encephalocoele with/without facial clefts. Three pathogenic mechanisms have been proposed: early amnion rupture, vascular disruption and embryonic dysgenesis. In this study we carried out the pathological evaluation of four fetuses with LBWC and their placentas. None of the cases had craniofacial defects. Three fetuses showed an abdominal wall defect with eventration of abdominal organs, cloacal exstrophy, absent external genitalia, abnormal internal genitalia, scoliosis and lower limb defects. One fetus showed failure of closure of both thoracic and abdominal walls with ectopia cordis, evisceration of left lung and abdominal organs, severe reduction defect of left arm, but normal colon, anus, bladder, genitalia and lower limbs. All cases had a short, malformed umbilical cord, incompletely covered by amnion. The umbilical vessels were embedded in an amniotic sheet which connected the skin margin of the anterior body wall defect to the placenta. These anomalies suggest an abnormal body stalk development as a pathogenic mechanism for LBWC. Prenatally, the abnormal fetoplacental attachment can be detected ultrasonographically by the end of the first gestational trimester. Postnatally, the examination of placenta, umbilical cord and membranes is crucial in confirming the diagnosis of LBWC.

Fetal amniotic adhesions. Their topographic concordance with regionally clustered malformations

BACKGROUND

The amniotic band disruption complex (ABDC) has been segregated recently into various phenotypes. In view of the pathogenic mechanisms that have been proposed, this study was designed to assess if it is one variable process or is composed of several distinct complexes.

METHODS

The 48 cases of fetuses with bands or placenta attached to fetal parts cited in this paper included nine new cases and 39 from the literature. They were organized first according to the embryonal topography of the malformations, then according to the position of the adhesions, and finally by the assessment of distances between the cases and between the malformations using the squared Euclidean distances for binary variables and cluster analysis.

RESULTS

In all three analyses, three groups were identified: 1) fetuses with cephalo-thoracic anomalies; 2) fetuses with caudal anomalies, and 3) fetuses with mixed anomalies. Nonetheless, overlap among the three groups was apparent. Thus, while fetuses with amniotic bands form three clusters, it appears that these are part of a spectrum and should be considered as variable manifestations of a single entity resulting from a single pathogenetic mechanism. An association was established between the localization of the adhesions and the malformations in various axes. Abdominoschisis, however, was not particularly related to adhesions at one or the other end of the fetus; a short umbilical cord was an almost universal finding. Single umbilical artery (SUA) was especially related to caudal adhesions and malformations (p = 0.004 and 0.001), as well as abdominoschisis (p = 0.002) and agenesis of the abdominal organs (p = 0.008).

CONCLUSIONS

The association between amniotic adhesions to the fetus and multiple malformations occurring predominantly in the same area suggest that the former are the cause of the latter. The association of abdominoschisis, as well as a short umbilical cord, with malformations and adhesions in all areas, suggests that these are secondary phenomena to generalized embryonal and fetal tension. SUA, however, with a specifically regional association, is more likely to be due to disruption from exposure in cases with abdominoschisis, often accompanying the loss of abdominal organs.

Clinical and epidemiological characteristics of infants with body wall complex with and without limb deficiency

The spectrum of defects in cases with limb body wall complex (LBWC) is quite variable since other anomalies are also observed in infants with LBWC, and some cases do not have limb deficiencies. Van Allen et al. [Am J Med Genet 1987;28:529-548] proposed that the diagnosis of LBWC (presence of body wall defects with evisceration of thoracic and/or abdominal organs, limb deficiency, and myelocystocele) should be based on the presence of two of three of the following anomalies: exencephaly or encephalocele with facial clefts, thoraco and/or abdominoschisis, and limb defects. This approach implies that an infant with encephalocele with facial clefts and limb defects may be considered as having LBWC, which I do not think is correct. I present the results of a clinical and epidemiological analysis aimed at identifying if, from an epidemiological perspective, it is possible to identify an entity which is characterized by the presence of abdominal wall defects along with other malformations including or not limb deficiencies. The result of this analysis allows us to consider that this entity should be characterized by the presence of abdominal wall defects with a variable spectrum of anomalies (with or without limb deficiencies) and, consequently, be called body wall complex (BWC). BWC includes cases regardless of their clinical pattern and the possible etiology or pathogenetic mechanism. Thus, the BWC entity does not include amniotic band sequence without body wall defects, but does include amniotic band sequence with body wall defects.

Umbilical cord agenesis in limb body wall defect

The term "Limb Body Wall Defect" (LBWD) refers to a variable group of congenital defects having in common abdomino- or thoraco-schisis and limb deficiency. Three general pathogenic mechanisms have been proposed for this disorder: amnion rupture, vascular disruption, and embryonic malformation. We hypothesize that there are subsets of "Limb Body Wall Defect," which have similar structural abnormalities and a common pathogenesis. We report on five cases of LBWD that were selected by using more restrictive criteria. An infant or fetus was included if it had abdominoschisis with a broad attachment of skin to amnion at the site of the abdominal wall defect, limb defects, and umbilical cord agenesis. Autopsy detected additional common structural defects. All had evisceration of the gastrointestinal structures into the extra-embryonic coelomic space with structural abnormalities of the intestines. All had scoliosis, thoracic deformities, pulmonary hypoplasia, and structural abnormalities of the cloaca and urogenital ridge. Four of five had meningomyelocele. Three had exstrophy of the cloaca. The four females all had ovarian agenesis and incomplete Mullerian fusion. None had normal development of the external genitalia. We propose that the pathogenesis was a primary malformation of body wall closure, with abnormal fusion of the amnion, which had occurred in the first month of development.

Association of prenatal vascular disruptions with decreased maternal age

Disruptions of fetal structures can create a variety of congenital anomalies. Some apparent prenatal vascular disruptions associate strongly with decreased maternal age, and are rare with older mothers. This is well-documented for gastroschisis, but similar findings with hydranencephaly suggest a general phenomenon that may also involve porencephaly, septo-optic dysplasia, early body stalk disruptions, certain hemifacial anomalies, and other findings. Prenatal vascular disruption may be a common cause of congenital anomalies, but its nature is unknown, and obvious environmental confounders associated with decreased maternal age may have only relatively small contributions. A protective effect for pregnancies of older mothers also remains a possibility.

Epidemiology of limb-body wall complex in Japan

Limb-body wall complex is a malformation of body and limbs with craniofacial defects. We describe here the epidemiology of this complex using the population-based registry data in the Kanagawa Birth Defects Monitoring Program during the period 1982-1991. Eleven infants (11/428,599 births) with the complex were ascertained in the study. The incidence and spectrum of the defects observed in our cases were similar to those of other studies. The parental ages in the study group were not significantly different from those in the general population. No teratogenic agents and factors were identified in the present study. Most cases were diagnosed prenatally.

Wisconsin Stillbirth Service Program: I. Establishment and assessment of a community-based program for etiologic investigation of intrauterine deaths

Although stillbirth is a common event, few programs have previously been established for the comprehensive etiologic investigation of intrauterine death. Fewer still have been prospective, unbiased in ascertainment, and consistent in protocol utilization. The Wisconsin Stillbirth Service Program was established in 1983 as a unique model for the investigation of the causes of stillbirth. This community-based, University-supported model for health care delivery is here described. Through it more than a thousand infants have been etiologically investigated. We demonstrate that a community-based program of stillbirth assessment can succeed, that compliance with recommended protocols is high and that a specific primary cause of fetal death can be demonstrated in about 40% of referrals. A majority of the established causes of intrauterine death are fetal etiologies. Furthermore, it appears that there are no substantial referral biases. Lack of such biases, together with the prospective, protocol driven nature of the program provides a unique population upon which to base estimates of the frequency of various etiologic diagnoses and classes and categories of cause.

Lower mesodermal defects: a common cause of fetal and early neonatal death

Among the first 1,130 referrals to the Wisconsin Stillbirth Service Program 17 infants have been recognized to share phenotypic characteristics involving the genital, urinary, lower gastrointestinal, and axial skeletal systems. The pattern of abnormalities identified appears to be limited to structures sharing a common embryologic origin. These features, for the most part, are shown to be non-randomly associated. No clearly definable sub-groups within this population are demonstrable. The pattern of abnormalities is defined to include abnormalities of the following structures as pathogenetically primary features: lumbosacral vertebrae, kidneys, ureters, uterus/fallopian tubes, vagina, bladder, urethra, adrenals, gonads, anorectum, external genitalia, and umbilical arteries. An embryologic mechanism is proposed which explains this non-random association as arising secondary to disruption of structures derived from the lower portion of the primitive intraembryonic mesoderm. The Lower Mesodermal Defects Sequence appears to be a rather common (and under-recognized) cause of stillbirth and immediate neonatal death.

Wisconsin Stillbirth Service Program: II. Analysis of diagnoses and diagnostic categories in the first 1,000 referrals

The Wisconsin Stillbirth Service Program has provided a mechanism for the collection and analysis of unbiased and representative information concerning stillborn infants. Generated diagnoses and diagnostic categories within the first 1,000 referrals (including 789 stillbirths) is summarized here. Among all referred stillborns, 24.5% were found to have an identifiable intrinsic fetal cause of death. Specific diagnoses were extraordinarily heterogeneous, with about 85 different processes identified with this group. No single diagnosis was found in more than 1 1/2% of the evaluated stillborns. Distribution by classes of fetal causes (as a percent of all fetal causes in stillborns) included malformation syndromes in 44%, single malformations and defined sequences in 34%, disruptions in 10%, and dysplasias in 3%. The heterogeneity of syndromic causes is illustrated, examples of previously undescribed syndromic processes provided and the problems experienced in generating specific diagnoses discussed. Specific single malformations, sequences, disruptions, and dysplasias are also tabulated and illustrated. Distribution by etiologic categories (as a percent of all fetal causes in stillborns) included defined sporadic conditions in 29%, cytogenetic aberration in 25%, presumed multifactorial processes in 12%, Mendelian disorders in 5%, and environmental events in less than 4%. A fourth of all fetal causes could not be sufficiently defined to allow for certainty in assigning a specific etiologic category. The materials summarized provide reference data regarding the frequency of classes and categories of fetal diagnoses generated from an unbiased and non-selected series of stillborns.

Limb body wall complex: a critical review and a nosological proposal

The analysis of the literature on limb body wall complex reveals a varied and rather confused spectrum of cases. However, we noticed the presence of at least 2 clearly distinguishable phenotypes. The first phenotype shows craniofacial defects and amniotic bands and/or adhesion; the second--without craniofacial defects--presents urogenital anomalies, anal atresia, and abdominal placental attachment, together with a persistence of the extra-embryonic coelom. We think these 2 phenotypes are the consequence of different pathogenetic mechanisms. The pathogenesis of the first type can be related to an early vascular disruption, while the pathogenesis of the second one is attributable to an intrinsic embryonal maldevelopment. Eight cases of the second phenotype were identified and the pathological findings proving this maldevelopmental origin are described.

Omphalocele and gastroschisis: a collaborative study of five Italian congenital malformation registries

During 1984-1989, 116 cases of omphalocele and 42 cases of gastroschisis were detected among 736,760 consecutive births in the area covered by five Italian congenital malformation registries. The prevalence rate was 1.6 per 10,000 for omphalocele and 0.6 per 10,000 for gastroschisis. Three additional cases were detected among spontaneous abortions, giving a total of 117 cases of omphalocele and 44 of gastroschisis. No variations in prevalence rates were observed among registries. A cluster of omphalocele was found in 1989 in Firenze. All cases were sporadic except for one infant with two sibs with Beckwith-Wiedemann syndrome. A predominance of male infants was observed for both defects. This study confirms the very young maternal age for isolated gastroschisis as compared to that for omphalocele and controls. Birth weight and the percentage of small-for-date is different among isolated gastroschisis, omphalocele and controls. Associated anomalies occurred in 45 cases of omphalocele and 11 cases of gastroschisis. Our data confirm the association of omphalocele with trisomies 13 and 18. Twelve cases of omphalocele and gastroschisis with associated limb defects were classified as limb body wall complex. The possible differences in etiopathology between omphalocele and gastroschisis, both isolated and associated, are discussed.

Structural anomalies resulting from vascular disruption

A diverse yet distinctive group of disorders and structural anomalies result from vascular disruption of embryonic and fetal blood vessels. The extent of damage, timing in gestation, and the mechanism of vascular disruption all determine the nature of the resultant structural anomalies. The developing human remains susceptible throughout pregnancy to teratogenic agents and events that alter uterine, placental, and embryonic or fetal circulation.

Further evidence that arthrogryposis multiplex congenita in the human sometimes is caused by an intrauterine vascular accident

A 7 1/2-year-old girl with arthrogryposis multiplex congenita of the amyoplasia type in association with intestinal atresias, gastroschisis, Möbius anomaly, and hypoplasia of the pectoral, biceps, and deltoid muscles is described. Several combinations of these birth defects have been previously described. There is considerable evidence that gastroschisis, intestinal atresia, Poland sequence, and Möbius anomaly each has a vascular pathogenesis. Based on the associations seen in this child and past reports of more limited, similar cooccurrences, we suggest that arthrogryposis multiplex congenita may sometimes be caused by an intrauterine vascular catastrophe.

Constrictive amniotic bands, amniotic adhesions, and limb-body wall complex: discrete disruption sequences with pathogenetic overlap

In a fetopathologic evaluation of 18 cases with amniotic bands, we discerned 3 types of lesions: (1) constrictive tissue bands, (2) amniotic adhesions, and (3) more complex anomaly patterns, designated as limb-body wall complex (LBWC). Constrictive bands are caused by primary amnion rupture with subsequent entanglement of fetal parts (mostly limbs) by shriveled amniotic strands. Adhesive bands are the result of a broad fusion between disrupted fetal parts (mostly cephalic) and an intact amniotic membrane. Most of the craniofacial defects (encephaloceles and/or facial clefts) occurring in these fetuses are not caused by constrictive amniotic bands, but are the result of a vascular disruption sequence with or without cephalo-amniotic adhesion. Our observations confirm the fact that amnion rupture is not a conditio sine qua non for the development of LBWC. However, LBWC is often complicated by rupture of the unsupported amnion with ensuing formation of constrictive bands. We think that the concept that considers the 3 lesions in question as a single pathogenetic entity is erroneous and will inevitably lead to a never-ending debate between followers of the 2 prevailing theories. In our view, the theories of Streeter and Torpin are not mutually exclusive but rather apply to different types of lesions. The recognition of constrictive amniotic bands, amniotic adhesions, and LBWC as discrete but often combined disruption sequences with important pathogenetic overlap may resolve many dilemmas in interpretation when a fetus exhibits classical constrictive bands beside more severe defects.

Etiologic complexities of diaphragmatic defects: right diaphragmatic hernia, pulmonary hypoplasia/agenesis, and hydrocephalus in sibs

Here we review the complexities of diaphragmatic defects and describe sibs with small, right diaphragmatic defects with pulmonary hypoplasia/agenesis and hydrocephalus. Despite a poor initial prognosis, the propositus has progressed remarkably well. Antenatal sonographic study detected hydrocephalus but not the diaphragmatic defect in the sib of the propositus. Because diaphragmatic defects are most commonly found in association with other anomalies and may occur in association with chromosome anomalies careful workup of all affected infants is crucial for accurate genetic counseling.

Limb body-wall complex in association with sirenomelia sequence

Limb body-wall complex and sirenomelia sequence are uncommon birth defects and their association is extremely rare. Their overlapping manifestations and their concurrence in our patient suggest that they share a common cause and belong to a group of pathologically closely related conditions. Embryonic vascular disruption may be a common pathogenesis in both anomalies.