Complex malformations involving the fetal body wall - definition and classification issues

Prenatal diagnosis of acrania/exencephaly/anencephaly sequence (AEAS): additional structural and genetic anomalies

OBJECTIVES

To analyse additional structural and genetic anomalies in fetuses with acrania/exencephaly/anencephaly sequence (AEAS).

METHODS

A retrospective analysis of 139 fetuses with AEAS diagnosed between 2006 and 2020 in a single tertiary referral ultrasound department.

RESULTS

The median gestational age at diagnosis decreased from 15 weeks in 2006 to 13 weeks in 2020 (- 0.21 per each year; p = 0.009). In 103 fetuses, the defects were limited to the neural tube (NTD) (74.1%), in 36 fetuses (25.9%), there were additional structural non-NTD anomalies. The most common were ventral body wall defects present in 17.8% (23/139), followed by anomalies of the limbs (7.2%; 10/139), face (6.5%; 9/139) and heart (6.5%; 9/139). Genetic anomalies were diagnosed in 7 of the 74 conclusive results (9.5%; 7/74; trisomy 18, n = 5; triploidy, n = 1; duplication of Xq, n = 1). In univariate logistic regression models, male sex, limb anomalies and ventral body wall defects significantly increased the risk of genetic anomalies (OR 12.3; p = 0.024; OR 16.5; p = 0.002 and OR 10.4; p = 0.009, respectively).

CONCLUSIONS

A significant number of fetuses with AEAS have additional structural non-NTD anomalies, which are mostly consistent with limb body wall complex. Genetic abnormalities are diagnosed in almost 10% of affected fetuses and trisomy 18 is the most common aberration. Factors that significantly increased the odds of genetic anomalies in fetuses with AEAS comprise male sex, limb anomalies and ventral body wall defects.

Current Perspectives of Prenatal Sonography of Umbilical Cord Morphology

The umbilical cord constitutes a continuation of the fetal cardiovascular system anatomically bridging between the placenta and the fetus. This structure, critical in human development, enables mobility of the developing fetus within the gestational sac in contrast to the placenta, which is anchored to the uterine wall. The umbilical cord is protected by unique, robust anatomical features, which include: length of the umbilical cord, Wharton’s jelly, two umbilical arteries, coiling, and suspension in amniotic fluid. These features all contribute to protect and buffer this essential structure from potential detrimental twisting, shearing, torsion, and compression forces throughout gestation, and specifically during labor and delivery. The arterial components of the umbilical cord are further protected by the presence of Hyrtl’s anastomosis between the two respective umbilical arteries. Abnormalities of the umbilical cord are uncommon yet include excessively long or short cords, hyper or hypocoiling, cysts, single umbilical artery, supernumerary vessels, rarely an absent umbilical cord, stricture, furcate and velamentous insertions (including vasa previa), umbilical vein and arterial thrombosis, umbilical artery aneurysm, hematomas, and tumors (including hemangioma angiomyxoma and teratoma). This commentary will address current perspectives of prenatal sonography of the umbilical cord, including structural anomalies and the potential impact of future imaging technologies.

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.

Prenatal diagnosis and clinical significance of cephalocele-A single institution experience and literature review

OBJECTIVES

To determine the frequency of genetic and additional structural abnormalities as well as pregnancy outcomes in fetuses with prenatally diagnosed cephalocele.

METHODS

A retrospective analysis of data retrieved from ultrasound examinations and genetic testing in fetuses with cephalocele diagnosed between 2006 and 2018 in a tertiary referral hospital along with a systematic literature search in the PubMed database on fetuses with prenatally diagnosed cephalocele.

RESULTS

Twenty-one out of 36 fetuses were found to have additional structural anomalies (58.3%). In four fetuses, anomalies were consistent with limb-body wall complex, in five with Meckel-Gruber syndrome, and in one with amniotic band syndrome. Genetic abnormalities were present in 11.1% of fetuses (trisomy 6; microdeletion 22q11.21; microduplication 16p13.11; pathogenic variant in gene CC2D2A). Twenty-eight pregnancies were terminated (77.8%; 28/36); two were miscarried (5.6%; 2/36). All six children from pregnancies that continued were liveborn but only two survived the surgery and developed neurological sequence. Overall survival rate was 25% (2/8) with 0% intact survival.

CONCLUSIONS

Additional structural anomalies are common in fetuses with cephalocele. A significant number of fetuses have genetic abnormalities, and a detailed genetic testing should be performed in all cases. The prognosis is poor with high mortality rate and 0% intact survival.

Fetal MRI in the Identification of a Fetal Ventral Wall Defect Spectrum

Objective  To ascertain if useful criteria for prenatal diagnosis of fetal ventral body wall defects (VBWDs) exists by reviewing published literature on diagnosis of VBWD as compared with our own diagnostic experience. Study Design  A comprehensive literature review of diagnostic criteria of fetal VBWD including pentalogy of Cantrell (POC), omphalocele, exstrophy, imperforate anus, spina bifida (OEIS), cloacal exstrophy, limb-body wall complex (LBWC), and body stalk anomaly was performed followed by a retrospective review of all fetal magnetic resonance imaging (MRI) examinations from our medical center over a 2-year period. Results  Classically, OEIS is omphalocele, bladder exstrophy, imperforate anus, and spina bifida. POC is defects of the supraumbilical abdomen, sternum, diaphragm, pericardium, and heart. LBWC is two of the following: exencephaly or enencephaly with facial clefts, thoracoschisis or abdominoschisis, and limb defects. Twenty-four cases of VBWD on MRI over a 24-month period were identified with seven cases involving defects of additional organ systems. Six of these seven cases demonstrated findings from two or more of the traditional diagnoses POC, OEIS, and LBWC making diagnosis and counseling difficult. Conclusion  There is a lack of consensus on useful diagnostic criteria within the published literature which is reflected in our own diagnostic experience and poses a challenge for accurate prenatal counseling.