A case of body stalk anomaly at 10 weeks of gestation

Amniotic sac diameter reference interval in early pregnancy between 7 and 10 weeks' gestation

OBJECTIVE

To establish a normal reference interval for amniotic sac diameter (ASD) between 7 + 0 and 9 + 6 weeks' gestation and its relative size in relation to gestational sac diameter (GSD) and the embryo crown-rump length (CRL).

METHODS

This was a prospective, cross-sectional study of consecutive women presenting to the Early Pregnancy Unit, University College Hospital, London, UK, between August 2022 and June 2023. We included live, normally sited, singleton pregnancies with a normal 20-week anomaly scan. We collected 120 cases per gestational week, from 7 + 0 to 9 + 6 weeks' gestation, totaling 360 cases. We performed an inter- and intraobserver variability assessment in the measurement of mean ASD in 30 patients. Regression analyses were used to establish reference intervals for GSD and CRL, ASD and CRL, GSD and ASD, and GSD/ASD ratio and CRL. A fitted regression line was calculated, along with a 90% prediction interval and R2 value.

RESULTS

There was good interobserver agreement (mean ± SD difference, 0.007 ± 1.105 mm (95% limits of agreement (LoA), -2.160 to 2.174 mm)) and good intraobserver agreement for Observer A (mean ± SD difference, -0.080 ± 0.741 mm (95% LoA, -1.532 to 1.372 mm)) and Observer B (mean ± SD difference, -0.014 ± 0.919 mm (95% LoA, -1.814 to 1.786 mm)) in the measurement of mean ASD. Regression analyses showed a statistically significant association between each pair of values (P < 0.001 for all). There was a significant quadratic association between mean GSD and CRL (R2 = 56%), mean GSD and ASD (R2 = 60%) and GSD/ASD ratio and CRL (R2 = 68%), and a significant cubic association between mean ASD and CRL (R2 = 90%). The regression equations were used to quantify the values of ASD and GSD/ASD ratios for a range of CRL values and gestational ages.

CONCLUSION

Our study has produced comprehensive reference intervals for amniotic sac size in early pregnancy, which could be used in routine clinical practice. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Analysis of characteristic features in ultrasound diagnosis of fetal limb body wall complex during 11-13+6 weeks

BACKGROUND

Limb body wall complex (LBWC) is a fatal malformation characterized by major defects in the fetal abdominal or thoracic wall, visceral herniation, significant scoliosis or spina bifida, limb deformities, craniofacial deformities, and umbilical cord abnormalities (short or absent umbilical cord). Early diagnosis of this condition is of great clinical significance for clinical intervention and pregnancy decision-making. With the rapid development of fetal ultrasound medicine, early pregnancy (11-13⁺⁶ wk) standardized prenatal ultrasound examinations have been widely promoted and applied.

AIM

To explore the value of prenatal ultrasound in the diagnosis of fetal LBWC syndrome during early pregnancy.

METHODS

The ultrasonographic data and follow-up results of 18 cases of fetal LBWC diagnosed by prenatal ultrasound during early pregnancy (11-13⁺⁶ wk) were retrospectively analyzed, and their ultrasonographic characteristics were analyzed.

RESULTS

Among the 18 fetuses with limb wall abnormalities, there were spinal dysplasia (18/18, 100%), varying degrees of thoracoschisis and gastroschisis (18/18, 100%), limb dysplasia in 6 cases (6/18, 33%), craniocerebral malformations in 4 cases (4/18, 22%), thickening of the transparent layer of the neck in 5 cases (5/18, 28%), and umbilical cord abnormalities in 18 cases (18/18, 100%), single umbilical artery in 5 cases.

CONCLUSION

Prenatal ultrasound in early pregnancy can detect LBWC as early as possible, and correct prenatal evaluation provides important guidance value for pregnancy decision-making and early intervention.

Anatomy-based diagnostic criteria for complex body wall anomalies (CBWA)

BACKGROUND

Precise diagnosis and classification of CBWA cases can be challenging. BSA are considered when there is a body wall anomaly, skeletal abnormalities, and the umbilical cord is anomalous, absent or rudimentary, and LBWC when there is a body wall and structural limb anomalies with or without craniofacial abnormalities.

METHODS

PubMed was searched for body stalk anomalies, limb body wall complex, body stalk anomalies and amniotic band syndrome, and limb body wall complex and amniotic band syndrome. Sixty nine articles were selected and reviewed. This article systematically classifies the variants of CBWA in 218 cases, the study is based on the embryological and anatomical criteria established by Martín-Alguacil and Avedillo to study BSA in the pig.

RESULTS

Eight different BSA presentation were defined. One hundred and eighty nine cases were classified as BSA, from which five were Type I, nine Type II, 20 Type III, 57 Type IV, 11Type V, 24 Type VI, 11 Type VII, and 52 Type VIII. Twenty six cases presented cranial phenotype, 114 abdominal phenotype, 42 cranio/abdominal overlapping phenotype, and five without defined phenotype. In addition, 52 BSA cases presented some kind of spinal dysraphism (SPDYS) and were classified as BSA/SPDYS, most of these cases did not show structural limb anomalies, except for three cases and were classified as LBWC/SPDYS.

CONCLUSION

This morphology-based classification represents a useful tool for clinical diagnosis, it helps to quantify and to evaluate CBWA in a precise, objective manner.

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.

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.

Monoamniotic twins discordant for body stalk anomaly

Body stalk anomaly is a rare malformation. This anomaly in monozygotic twins is extremely unusual. We describe a case of monoamniotic pregnancy discordant for body stalk anomaly diagnosed at 11 weeks. Ultrasound showed a fetus with a large anterior abdominal wall defect, anomaly of the spine and no evidence of lower extremities and other with a normal morphology. As far as our concern, only three monoamniotic pregnancies discordant for this malformation were reported. Our case represents the fourth reported monoamniotic pregnancy discordant for body stalk anomaly with diagnosis made by ultrasound and the second diagnosed in the first trimester.

Fetal abdominal wall defects

The most common fetal abdominal wall defects are gastroschisis and omphalocele, both with a prevalence of about three in 10,000 births. Prenatal ultrasound has a high sensitivity for these abnormalities already at the time of the first-trimester nuchal scan. Major unrelated defects are associated with gastroschisis in about 10% of cases, whereas omphalocele is associated with chromosomal or genetic abnormalities in a much higher proportion of cases. Challenges in management of gastroschisis are related to the prevention of late intrauterine death, and the prediction and treatment of complex forms. With omphalocele, the main difficulty is the exclusion of associated conditions, not all diagnosed prenatally. An outline of the postnatal treatment of abdominal wall defects is given. Other rarer forms of abdominal wall defects are pentalogy of Cantrell, omphalocele, bladder exstrophy, imperforate anus, spina bifida complex, prune-belly syndrome, body stalk anomaly, and bladder and cloacal exstrophy; they deserve multidisciplinary counselling and management.

Novel exomphalos genetic mouse model: the importance of accurate phenotypic classification

BACKGROUND

Rodent models of abdominal wall defects (AWD) may provide insight into the pathophysiology of these conditions including gut dysfunction in gastroschisis, or pulmonary hypoplasia in exomphalos. Previously, a Scribble mutant mouse model (circletail) was reported to exhibit gastroschisis. We further characterise this AWD in Scribble knockout mice.

METHOD

Homozygous Scrib knockout mice were obtained from heterozygote matings. Fetuses were collected at E17.5-18.5 with intact amniotic membranes. Three mutants and two control fetuses were imaged by in amnio micro-MRI. Remaining fetuses were dissected, photographed and gut length/weight measured. Ileal specimens were stained for interstitial cells of Cajal (ICC), imaged using confocal microscopy and ICC quantified.

RESULTS

127 fetuses were collected, 15 (12%) exhibited AWD. Microdissection revealed 3 mutants had characteristic exomphalos phenotype with membrane-covered gut/liver herniation into the umbilical cord. A further 12 exhibited extensive AWD, with eviscerated abdominal organs and thin covering membrane (intact or ruptured). Micro-MRI confirmed these phenotypes. Gut was shorter and heavier in AWD group compared to controls but morphology/number of ICC was not different.

DISCUSSION

The Scribble knockout fetus exhibits exomphalos (intact and ruptured), in contrast to the original published phenotype of gastroschisis. Detailed dissection of fetuses is essential ensuring accurate phenotyping and result reporting.

A fetal autopsy case of body stalk anomaly

Body stalk anomaly (BSA) is a sporadic polymalformative syndrome incompatible with extrauterine life. In utero detection of BSA by two-dimensional and three-dimensional ultrasonography and magnetic resonance imaging has been well documented. We herein describe a case of body stalk anomaly diagnosed at autopsy. The fetus had a large anterior midline abdominal wall defect with eventration of the visceral organs into the amnio-peritoneal sac and a completely absent umbilical cord. The associated anomalies included club foot, absent diaphragm, genitourinary, and gastrointestinal defects. The observed congenital anomalies supported the theory of embryonic dysgenesis as the etiologic factor. One of the major objectives in the performance of fetal autopsy is to be able to detect abnormalities that can have implications in future pregnancies. Despite the negligible familial recurrence rate of the broad spectrum of anomalies associated with this abdominal wall defect, the present case of fetal autopsy indeed delights to serve the living.

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.

Three-dimensional multiplanar ultrasound in a limb-body wall complex fetus: clinical evidence for counseling

A rare dysmorphologic fetal anomaly at the 17th week of gestation was suspected during a second trimester routine scan for fetal and maternal screening data. First findings were significant for a severe abdominal wall defect, limb and foot compromised positions. Fetal biometry was appropriate in biparietal diameter and head circumference measurements; the long upper bones were normal both for length and development. The patient was referred to a prenatal unit to complete the sonographic diagnosis. Two- and three-dimensional sonographic investigations were performed and techniques were complementary for fetal maldevelopment specification. Limb-body wall complex with lumbosacral spine torsion and lower limbs with severely abnormal features were identified. With 2D color Doppler, a heart defect was confirmed and the umbilical cord was missing from the amniotic cavity. An invasive procedure by amniocentesis was made to ascertain alpha-fetoprotein levels and fetal karyotype. Following parental counseling, pregnancy was terminated and feto-pathological examination confirmed the sonographic diagnosis. The 17-week fetus affected by limb-body wall complex is reported herein; 2D and 3D scans of the fetus identified organ displacement due to a combination of very early events.

Body stalk anomaly diagnosed in the 2nd trimester

We examined a 20-year-old primigravida by ultrasound at 21 weeks of gestation during routine anomaly scanning. Several fetal deformities were demonstrated: the upper part of the body was in the amniotic cavity, while the lower part was in the celomic cavity. A large abdominal wall defect was detected with herniation of the liver and the intestine. The limbs were deformed, the spine had severe kyphoscoliosis, and the umbilical cord was very short. These findings were suggestive of a body stalk anomaly. Termination of the pregnancy was offered and decided by the parents. The pathology report confirmed the ultrasonographic diagnosis.

Prenatal ultrasound diagnosis and management of body stalk anomaly: analysis of nine singleton and two multiple pregnancies

OBJECTIVE

To determine prenatal ultrasonographic features and management of fetuses with body stalk syndrome in singleton and multiple gestations.

METHODS

In a retrospective chart analysis we reviewed all cases with body stalk anomaly diagnosed in our prenatal unit between 1994 and 2001. During this time period we adopted a uniform approach to the investigation of cases of body stalk anomaly, including amniocentesis or chorionic villus sampling (CVS) for fetal karyotyping. A general schematic sonographic examination was performed to search for fetal abnormalities and was followed by detailed two-dimensional and color-coded Doppler echocardiography. Nuchal translucency (NT) measurements were performed before 14 weeks of gestation. Postmortem examinations of fetuses were performed following termination by induction with prostaglandin.

RESULTS

Eleven fetuses with body stalk anomaly were diagnosed, including two multiple pregnancies complicated by discordant body stalk anomaly. The typical ultrasonographic features were a major abdominal wall defect, severe kyphoscoliosis, limb abnormalities, neural tube defects, and a malformed, short umbilical cord with a single artery. None of the fetuses demonstrated craniofacial defects. All placentae that were examined showed evidence of persistence of the extra-embryonic celomic cavity. NT measurements were abnormal in all cases. Fetal karyotyping was normal in ten cases. In one case CVS showed a mosaic trisomy 2 (46,XX/47,XX,+ 2). Selective fetocide was performed in one trichorionic-triamniotic triplet pregnancy in early gestation, which was followed by normal development of the remaining healthy dichorionic-diamniotic twins. In a monochorionic-diamniotic twin pregnancy with one affected fetus ultrasound surveillance showed the normal development of the unaffected twin.

CONCLUSIONS

We present a large series of body stalk anomaly, including multiple gestations, with thoraco- and/or abdominoplacental attachment and without craniofacial defects. This specific phenotype may be explained by embryonic maldevelopment. The typical features of body stalk anomaly can be detected by ultrasound by the end of the first trimester, which is important for patient management. Consequently, this anomaly should be distinguished from other fetal abdominal wall defects.

Monozygotic twins discordant for body stalk anomaly

We report on two cases of monozygotic twins discordant for body stalk anomaly, diagnosed prenatally in a multicenter ultrasound screening study at 10-14 weeks of gestation. Ultrasound showed a large abdominal wall defect with most of the abdominal contents and almost half of the body in the celomic cavity, in association with severe kyphoscoliosis and a very short umbilical cord. Both pregnancies were managed expectantly and delivered by Cesarean section. The abnormal babies died soon after birth and autopsy confirmed the sonographic diagnosis. Body stalk anomaly in twins is extremely rare. These are, to our knowledge, the first cases reported on monozygotic twins discordant for this anomaly, indicating that the incomplete twinning theory cannot uniformly explain the pathogenesis of the body stalk in twins.