Investigation of a transient increase in omphalocele prevalence in a birth cohort of TRICARE beneficiaries

BACKGROUND

The Department of Defense Birth and Infant Health Research (BIHR) program leverages medical encounter data to conduct birth defect surveillance among infants born to military families. Omphalocele is a major abdominal wall defect with an annual prevalence of ~2 per 10,000 births in BIHR data, but an unexpected increase was observed during 2017-2019, reaching 6.4 per 10,000 births in 2018. To investigate this transient increase in prevalence, this study aimed to validate the omphalocele case algorithm among infants born 2016-2021.

METHODS

Omphalocele cases were identified by ICD-10 code Q79.2 (exomphalos) on one inpatient or two outpatient infant encounter records and validated using parental and infant electronic health records. Characteristics of true and false positive cases were assessed using bivariate analyses and compared over time.

RESULTS

Of 638,905 live births from 2016 to 2021, 230 met the ICD-10 case definition for omphalocele; 138 (60.0%) cases were eligible for validation, of which 68 (49.3%) were true positives. The geometric mean time from birth to first ICD-10 omphalocele diagnosis was 1.1 (standard error [SE] 0.1) days for true positives and 11.9 (SE 3.1) days for false positives. Among the 70 false positives, 36 (51.4%) were cases of confirmed umbilical hernia; rates of umbilical hernia and delayed omphalocele diagnoses (>30 days after birth) were elevated among false positives during 2017-2019.

CONCLUSIONS

Higher misuse of ICD-10 code Q79.2 during 2017-2019 likely influenced the associated increase in omphalocele prevalence. Timing of diagnosis should be considered for omphalocele case definitions using medical encounter data.

Abdominal Wall Defects: A Review of Current Practice Guidelines

The 2 most common congenital abdominal wall defects are gastroschisis and omphalocele. Gastroschisis is a defect in the abdominal wall with exposed abdominal contents. Mortality rates are low but lengths of stay are often prolonged by bowel dysmotility and other intestinal abnormalities in complicated cases. Omphalocele is a defect through the umbilical cord with herniated abdominal contents covered by a sac. It is associated with other genetic abnormalities and other anomalies that can lead to significant morbidity and mortality. Prenatal diagnosis in both conditions allows for improved prenatal consultation and coordinated perinatal care to improve clinical outcomes.

Delayed Closure of Giant Omphaloceles in West Africa: Report of Five Cases

Giant omphalocele (GO) management is controversial and not easy. Conservative management at birth and delayed surgical closure is usually mandatory. Postponed surgery may be challenging and carry the risk of intensive care treatment. We report on five children who were treated in our department for GO between 2000 and 2010. Initially, the patients were managed conservatively in West Africa. Delayed closure of the ventral hernia was performed in Switzerland after patient transfer through a nongovernmental organization. Fascial closure was performed at the median age of 23 months. Median diameter of the hernias was 10 × 10 cm ranging from 10 × 8 cm to 24 × 15 cm. Four (80%) patients had associated anomalies. Three children needed mechanical ventilation in the intensive care unit after surgery. Median hospitalization was 19 days. Complications were seen in two patients. The follow-up showed no recurrence of ventral hernia. There was no mortality.

This report shows that conservative management of a GO at birth with delayed closure of the ventral hernia after transferring the patients to a European center is a safe approach for West African children and avoids life-threatening procedures. Delayed closure of a GO may be nevertheless challenging everywhere.

Prenatal Prediction of the Type of Omphalocele Closure by Different Medical Consultants

INTRODUCTION

To evaluate differences between consultants of different disciplines in the prenatal prediction of the type of postnatal surgical closure of an omphalocele.

MATERIAL AND METHODS

Twenty-one images of prenatally detected omphaloceles prior to 24 weeks of gestation were included. A standardized form provided known prenatal information and an ultrasound image for each case. Nineteen consultants were asked to assess the probability of primary closure of an omphalocele and to state which information was the most important for their assessment.

RESULTS

Primary closure (13/21 images) was predicted correctly in 5/13 images. The number of correct predictions per image ranged from 63 to 89%. The type of closure was predicted correctly in 7/8 images of cases which were not closed primarily, ranging from 58 to 84% correct predictions per image. There was no significant difference between consultants of different disciplines. Individual accuracy ranged from 10 to 62%. The consultants regarded omphalocele content as the most important information (34%) for counseling.

DISCUSSION

The consultants did not differ in their prenatal judgment of the primary closure of an omphalocele. The consultants tended to be too negative in their assessment, since 75% assessed the probability of primary closure overall to be <60%, whereas 62% of the cases were primarily closed. Omphalocele content was the most important information for the consultants' judgment.

Interrupted inferior vena cava in fetuses with omphalocele. Case series of fetuses referred for fetal echocardiography and review of the literature

OBJECTIVES

Congenital heart disease is reported in 15-45% of omphalocele cases. Associated abnormalities of systemic veins have occasionally been reported in children and rarely documented in the fetus. We report a case series of interrupted inferior vena cava (Int-IVC) in association with omphalocele and review the literature.

METHODS

From our fetal database we identified all cases of omphalocele referred for fetal echocardiography (FE) between 1997 and 2012. We reviewed pre and postnatal medical records and performed a literature search from 1975 to present to identify previous relevant publications.

RESULTS

Of 9627 fetuses referred for FE, 34 had an omphalocele. Gestational age at FE was 17(+6) to 26(+4)weeks. Seven of the 34 fetuses were shown to have an Int-IVC with azygos continuation to a right-sided superior vena cava (SVC). The heart was structurally normal in all but one case. The abdominal wall defect was large and contained liver in all. There were three fetal demises and one neonatal death. Three cases were operated successfully. Since 1975, we identified 12 publications reporting omphalocele with systemic venous abnormalities. Abnormal IVC angulation may lead to surgical complications. Failure of IVC formation is likely to be a developmental rather than a situs abnormality. Int-IVC with a dilated azygos influences venous access and may predispose to venous thrombosis.

CONCLUSION

We have documented an association between large omphalocele and Int-IVC with azygos continuation to the SVC. In this small series, this did not have surgical implications. It will however, influence route of any future cardiac catheterisation and may have long-term implications.

Perinatal mortality in pregnancies with omphalocele: data from the Chinese national birth defects monitoring network, 1996-2006

Background

Previous studies on the mortality rate of omphalocele are limited. The risk of death of non-isolated omphalocele and that of cases of omphalocele that are diagnosed prenatally by ultrasound are unclear. This study aimed to estimate the perinatal mortality of pregnancies with omphalocele. This study also examined the potential risk of death of non-isolated omphalocele and that of cases that are prenatally diagnosed by ultrasound.

Methods

Data were retrieved from the national birth defects registry in China, for 1996–2006. Multinomial logistic regression was used to calculate the adjusted odds ratios (AORs) and 95% confidence intervals (CIs) between perinatal mortality and selected maternal and fetal characteristics.

Results

Among 827 cases of omphalocele, 309 (37.4%) cases resulted in termination of pregnancy and stillbirth, and 124 (15.0%) cases resulted in death in the first 7 days after delivery, yielding a perinatal mortality rate of 52.4% (95% CI: 49.0–55.8%). The late fetal death rate (LFDR) of omphalocele that was diagnosed prenatally by ultrasound was 15.91-fold (AOR: 15.91, 95% CI: 10.18–24.87) higher than that of postnatally diagnosed cases. The LFDR of non-isolated omphalocele was 2.64-fold (AOR: 2.64, 95% CI: 1.62–4.29) higher than that of isolated cases. For the early neonatal death rate, neonates with non-isolated omphalocele had a 2.96-fold (AOR: 2.96, 95% CI: 1.82–4.81) higher risk than isolated cases, but the difference between prenatal ultrasound diagnosis and postnatal diagnosis was not significant.

Conclusions

Selected fetal characteristics are significantly associated with the perinatal risk of death from omphalocele. Our findings suggest that improving pregnancy and delivery care, as well as management for omphalocele are important.

Genetic analysis of the role of Alx4 in the coordination of lower body and external genitalia formation

Although several syndromes include abnormalities of both the ventral body wall and external genitalia, the developmental bases of this correlation are largely unknown. Naturally occurring mutations in Aristaless-like 4 (Alx4, Strong's luxoid: Alx4^Lst) have ventral body wall and pelvic girdle abnormalities. We sought to determine whether the development of the genital tubercle (GT) and its derivatives, the external genitalia, is affected by this mutation. We thus performed genetic and tissue labeling analyses in mutant mice. Alx4^Lst/Lst mutants displayed hypoplasia of the dorsal GT and reduced expression of Fibronectin. We analyzed cell migration during GT formation by tissue labeling experiments and discovered that the cells located in the proximal segment of the umbilical cord (infra-umbilical mesenchyme) migrate toward the dorsal part of the GT. The Alx4^Lst/Lst mutants also displayed augmented expression of Hh signal-related genes. Hence, we analyzed a series of combinatorial mutants for Alx4, Sonic hedgehog (Shh) and GLI-Kruppel family member 3 (Gli3). These phenotype–genotype analyses suggested a genetic interaction between Alx4 and Hh signaling during GT formation. Moreover, Hh gain-of-function mutants phenocopied some of these phenotypes. These observations reveal novel information regarding the pathogenic mechanisms of syndromic lower ventral body malformations, which are largely unknown.

Fetal omphalocele in a common bottlenose dolphin (Tursiops truncatus)

A routine pregnancy ultrasound examination of a 30-yr-old, multiparous, common bottlenose dolphin, Tursiops truncatus, detected an approximately 16-wk (gestational age) fetus with an omphalocele, an abdominal wall defect at the base of the umbilical cord. Throughout the pregnancy, ultrasound allowed for identification of the omphalocele contents, which included a portion of the liver and intestinal loops. The maximum diameter of the omphalocele was 11.4 cm at an estimated 51-wk gestation. Color Doppler was utilized to study the blood flow within the omphalocele as well as diagnose an associated anomaly of the umbilical cord, which contained three vessels instead of four. Gross necropsy and histopathology confirmed the ultrasound diagnoses. This is the first report of an omphalocele in a T. truncatus fetus, and the first report of a fetal and umbilical cord anomaly diagnosed with ultrasound in a cetacean.

Outcome of fetal exomphalos diagnosed at 11-14 weeks of gestation

OBJECTIVE

To determine whether sonographic findings in cases of exomphalos detected at the 11-14-week scan can be used to guide pregnancy management.

METHODS

Retrospective study of cases of exomphalos identified from the Fetal Medicine Unit database, University College London Hospitals between January 1998 and January 2010. Pregnancy and neonatal data were ascertained from maternal and neonatal records. Fetal exomphalos was categorized into three groups: exomphalos associated with other major structural malformation(s), isolated exomphalos with increased nuchal translucency (NT) and isolated exomphalos with normal NT.

RESULTS

A total of 98 cases of exomphalos were identified, of which 45 (45.9%) were associated with other major structural malformation(s), identified antenatally. Isolated exomphalos was found with increased NT in 22 cases (22.4%) and with normal NT in 31 cases (31.6%). Of 80 (81.6%) fetuses that were karyotyped, 43 (53.8%) had a chromosomal abnormality; the most common aneuploidy was trisomy 18 (n = 31; 72.1%). Where exomphalos was associated with other major structural abnormalities, or was isolated with increased NT, the incidence of aneuploidy was high, at 78.9% and 72.2%, respectively. Cases of isolated exomphalos with normal NT were all euploid. In 21 cases (21.4%), exomphalos resolved later in pregnancy and none had apparent abnormalities at birth; isolated exomphalos persisted in only three neonates (3.1%).

CONCLUSIONS

The finding of a major structural abnormality or of increased NT in association with exomphalos in the first trimester implies a high risk of aneuploidy. Parents can be reassured that fetuses with isolated exomphalos and normal NT are likely to be euploid.

Emergency treatment of a ruptured huge omphalocele by simple suture of its membrane

BACKGROUND

The rupture of a huge omphalocele is an emergency that threatens the newborn baby's life. It constitutes a therapeutical concern in the absence of prosthesis especially in developing countries.

METHODS

We are reporting herein the case of a newborn baby that we managed in emergency successfully thanks to a simple treatment.

RESULTS

It was a huge omphalocele, ruptured during delivery, in a male newborn baby. We conducted a simple and conservative surgical treatment without prosthesis, which consisted of reconstruction of the omphalocele's membrane by closing it with absorbable suture materials. The suture of the omphalocele's membrane was followed by treatment with the Grob's method. This treatment saved the newborn baby's life. The total skinning was obtained after 3 months.

CONCLUSIONS

In case of rupture of huge omphalocele in absence of prosthesis, it is better to suture the membrane, and continue the treatment according to the Grob's method; the residual disembowelment can be repaired later.

Perinatal outcome in the live-born infant with prenatally diagnosed omphalocele

We compared perinatal outcomes between live-born nonisolated and isolated omphaloceles diagnosed during a prenatal ultrasound. Fetuses (n = 86) with omphalocele were identified between 1995 and 2007 at a single institution. Inclusion criteria were an omphalocele >14 weeks' gestation, available fetal and/or neonatal karyotype, and a live-born infant (n = 46). Perinatal outcomes were compared in nonisolated (n = 23) and isolated omphaloceles (n = 23). For all omphaloceles, the majority delivered after 34 weeks by cesarean. Mean birth weight (2782 versus 2704 g), median length of stay (27 versus 25 days), and mortality (two deaths in each group) were not different between the nonisolated and isolated groups (p > 0.05). In the nonisolated group, seven major anomalies were not confirmed postnatally. Of the prenatally diagnosed isolated omphaloceles, 8 (35%) were diagnosed with a syndrome or other anomalies after birth. The outcomes were similar in nonisolated and isolated prenatally diagnosed omphaloceles, but ultrasound did not always accurately determine the presence or absence of associated anomalies.

Review of the evidence on the closure of abdominal wall defects

Infants with congenital abdominal wall defects pose an interesting and challenging management issue for surgeons. We attempt to review the literature to define the current treatment modalities and their application in practice. In gastroschisis, the overall strategies for repair include immediate closure or delayed operative repair. The best level of data for gastroschisis is grade C and appears to support that there is no major difference in survival between immediate closure or delayed repair. In patients with omphalocele, the management techniques are more varied consisting of immediate closure, staged closure or delayed closure after epithelialization. The literature is less clear on when to use one technique over the other, consisting of mostly grade D and E data. In patients with omphalocele, a registry to collect information on patients with larger defects may help determine which of the management strategies is optimal.

Genetic analysis of Hedgehog signaling in ventral body wall development and the onset of omphalocele formation

Background

An omphalocele is one of the major ventral body wall malformations and is characterized by abnormally herniated viscera from the body trunk. It has been frequently found to be associated with other structural malformations, such as genitourinary malformations and digit abnormalities. In spite of its clinical importance, the etiology of omphalocele formation is still controversial. Hedgehog (Hh) signaling is one of the essential growth factor signaling pathways involved in the formation of the limbs and urogenital system. However, the relationship between Hh signaling and ventral body wall formation remains unclear.

Methodology/Principal Findings

To gain insight into the roles of Hh signaling in ventral body wall formation and its malformation, we analyzed phenotypes of mouse mutants of Sonic hedgehog (Shh), GLI-Kruppel family member 3 (Gli3) and Aristaless-like homeobox 4 (Alx4). Introduction of additional Alx4^Lst mutations into the Gli3^Xt/Xt background resulted in various degrees of severe omphalocele and pubic diastasis. In addition, loss of a single Shh allele restored the omphalocele and pubic symphysis of Gli3^Xt/+; Alx4^Lst/Lst embryos. We also observed ectopic Hh activity in the ventral body wall region of Gli3^Xt/Xt embryos. Moreover, tamoxifen-inducible gain-of-function experiments to induce ectopic Hh signaling revealed Hh signal dose-dependent formation of omphaloceles.

Conclusions/Significance

We suggest that one of the possible causes of omphalocele and pubic diastasis is ectopically-induced Hh signaling. To our knowledge, this would be the first demonstration of the involvement of Hh signaling in ventral body wall malformation and the genetic rescue of omphalocele phenotypes.

The 11-13-week scan: diagnosis and outcome of holoprosencephaly, exomphalos and megacystis

OBJECTIVE

To determine the prevalence and outcome of fetuses with holoprosencephaly, exomphalos and megacystis diagnosed at 11-13 weeks of gestation.

METHODS

As part of a prospective screening study for trisomy 21 in singleton pregnancies at 11 + 0 to 13 + 6 weeks' gestation, transabdominal ultrasound examination was performed to diagnose holoprosencephaly, exomphalos and megacystis. Fetal karyotype and pregnancy outcome in fetuses with these defects were examined.

RESULTS

Screening was carried out in 57 119 pregnancies. The prevalence of holoprosencephaly, exomphalos and megacystis was 1 : 1298, 1 : 381 and 1 : 1632, respectively. Chromosomal abnormalities, mainly trisomies 18 and 13, were found in 65.9% of fetuses with holoprosencephaly, in 55.3% with exomphalos and in 31.4% with megacystis. There was spontaneous resolution of the defect by 20 weeks in 92.5% of euploid fetuses with exomphalos containing only bowel and in 90% of the euploid fetuses with megacystis and bladder length of < or = 15 mm.

CONCLUSIONS

A high proportion of fetuses with holoprosencephaly, exomphalos and megacystis diagnosed at 11-13 weeks of gestation are aneuploid, but in the majority of cases exomphalos and megacystis represent temporary abnormalities that resolve spontaneously.

The outcomes of pregnancies following a prenatal diagnosis of fetal exomphalos in Western Australia

AIMS

To review the perinatal outcomes for prenatally diagnosed exomphalos from a single geographical region.

METHODS

Retrospective review of cases of prenatally identified exomphalos in the state of Western Australia in the ten-year period 1998-2007 using the medical databases of the sole tertiary obstetric and paediatric hospitals.

RESULTS

Ninety-four cases of prenatally identified exomphalos comprise this consecutive case series. Culture-proven karyotypic abnormalities occurred in 40 (42.6%) fetuses. No karyotypically abnormal fetus survived the neonatal period, with 33 of 40 (82.5%) pregnancies interrupted, five of 40 (12.5%) resulting in fetal demise and two (5%) neonatal deaths. For the 49 (52.1%) fetuses with a normal karyotype, 26 (53.1%) had associated abnormalities with termination occurring in 22 (84.6%). Prenatally isolated exomphalos was present in 23 cases (24.5%), with live birth in 15 cases (30.6% of euploid fetuses). Fourteen (93.3%) of the liveborn prenatally isolated exomphalos cases survived with no postoperative deaths, although four (28.5%) had significant abnormalities detected postdelivery and most have experienced childhood morbidity.

CONCLUSIONS

In the the majority of cases of prenatally detected exomphalos the pregnancy was interrupted secondary to chromosomal or structural abnormalities. In only 10.6% of prenatally recognised fetuses with exomphalos was the disorder truly isolated with neonatal survival occurring.