Gastroschisis: Clinical presentation and associations

Developmental regulation of cellular metabolism is required for intestinal elongation and rotation

Malrotation of the intestine is a prevalent birth anomaly, the etiology of which remains poorly understood. Here, we show that late-stage exposure of Xenopus embryos to atrazine, a widely used herbicide that targets electron transport chain (ETC) reactions, elicits intestinal malrotation at high frequency. Interestingly, atrazine specifically inhibits the cellular morphogenetic events required for gut tube elongation, including cell rearrangement, differentiation and proliferation; insufficient gut lengthening consequently reorients the direction of intestine rotation. Transcriptome analyses of atrazine-exposed intestines reveal misexpression of genes associated with glycolysis and oxidative stress, and metabolomics shows that atrazine depletes key glycolytic and tricarboxylic acid cycle metabolites. Moreover, cellular bioenergetics assays indicate that atrazine blocks a crucial developmental transition from glycolytic ATP production toward oxidative phosphorylation. Atrazine-induced defects are phenocopied by rotenone, a known ETC Complex I inhibitor, accompanied by elevated reactive oxygen species, and rescued by antioxidant supplementation, suggesting that malrotation may be at least partly attributable to redox imbalance. These studies reveal roles for metabolism in gut morphogenesis and implicate defective gut tube elongation and/or metabolic perturbations in the etiology of intestinal malrotation.

Five Hundred Patients With Gut Malrotation: Thirty Years of Experience With the Introduction of a New Surgical Procedure

OBJECTIVES

Define clinical spectrum and long-term outcomes of gut malrotation. With new insights, an innovative procedure was introduced and predictive models were established.

METHODS

Over 30-years, 500 patients were managed at 2 institutions. Of these, 274 (55%) were children at time of diagnosis. At referral, 204 (41%) patients suffered midgut-loss and the remaining 296 (59%) had intact gut with a wide range of digestive symptoms. With midgut-loss, 189 (93%) patients underwent surgery with gut transplantation in 174 (92%) including 16 of 31 (16%) who had autologous gut reconstruction. Ladd's procedure was documented in 192 (38%) patients with recurrent or de novo volvulus in 41 (21%). For 80 patients with disabling gastrointestinal symptoms, gut malrotation correction (GMC) surgery "Kareem's procedure" was offered with completion of the 270° embryonic counterclockwise-rotation, reversal of vascular-inversion, and fixation of mesenteric-attachments. Concomitant colonic dysmotility was observed in 25 (31%) patients.

RESULTS

The cumulative risk of midgut-loss increased with volvulus, prematurity, gastroschisis, and intestinal atresia whereas reduced with Ladd's and increasing age. Transplant cumulative survival was 63% at 10-years and 54% at 20-years with best outcome among infants and liver-containing allografts. Autologous gut reconstruction achieved 78% and GMC had 100% 10-year survival. Ladd's was associated with 21% recurrent/de novo volvulus and worsening (P > 0.05) of the preoperative National Institute of Health patient-reported outcomes measurement information system gastrointestinal symptom scales. GMC significantly (P ≤ 0.001) improved all of the symptomatology domains with no technical complications or development of volvulus. GMC improved quality of life with restored nutritional autonomy (P < 0.0001) and daily activities (P < 0.0001).

CONCLUSIONS

Gut malrotation is a clinicopathologic syndrome affecting all ages. The introduced herein definitive correction procedure is safe, effective, and easy to perform. Accordingly, the current standard of care practice should be redefined in this orphan population.

Change in prepregnancy body mass index and gastroschisis

PURPOSE

Maternal body mass index (BMI) is inversely associated with gastroschisis, but a causal relationship has not been established. As data demonstrating that a change in exposure status is related to a change in the frequency of the outcome can add to the evidence for causality, we conducted a case-control study of change in maternal BMI, assessed using interpregnancy change in BMI (IPC-BMI), and gastroschisis.

METHODS

Data for 258 gastroschisis cases and 2561 controls were obtained from the Texas Birth Defects Registry and vital records (2006-2012). Logistic regression was used to estimate the adjusted association between IPC-BMI and gastroschisis.

RESULTS

The continuous IPC-BMI variable was inversely associated with gastroschisis (adjusted odds ratio [aOR] = 0.90, 95% confidence interval [CI]: 0.86, 0.95). When assessed as a six-level categorical variable, with weight stable women as the referent, the odds of gastroschisis were higher following a BMI decrease of greater than 1 unit (aOR = 1.37, 95% CI: 0.91, 2.06) and lower after a BMI increase of ≥3 units (aOR = 0.62, 95% CI: 0.42, 0.94).

CONCLUSIONS

Our findings suggest that maternal change in BMI is associated with gastroschisis and, thus, add to the epidemiological evidence that can be used to inform our understanding of the relationship between BMI and gastroschisis.

A clinical-pathogenetic approach on associated anomalies and chromosomal defects supports novel candidate critical regions and genes for gastroschisis

BACKGROUND

Gastroschisis has been assumed to have a low rate of syndromic and primary malformations. We aimed to systematically review and explore the frequency and type of malformations/chromosomal syndromes and to identify significant biological/genetic roles in gastroschisis.

METHODS

Population-based, gastroschisis-associated anomalies/chromosomal defects published 1950-2018 (PubMed/MEDLINE) were independently searched by two reviewers. Associated anomalies/chromosomal defects and selected clinical characteristics were subdivided and pooled by race, system/region, isolated, and associated cases (descriptive analysis and chi-square test were performed). Critical regions/genes from representative chromosomal syndromes including an enrichment analysis using Gene Ontology Consortium/Panther Classification System databases were explored. Fisher's exact test with False Discovery Rate multiple test correction was performed.

RESULTS

Sixty-eight articles and 18525 cases as a base were identified (prevalence of 17.9 and 3% for associated anomalies/chromosomal defects, respectively). There were 3596 associated anomalies, prevailing those cardiovascular (23.3%) and digestive (20.3%). Co-occurring anomalies were associated with male, female, American Indian, Caucasian, prenatally diagnosed, chromosomal defects, and mortality (P < 0.00001). Gene clusters on 21q22.11 and 21q22.3 (KRTAP), 18q21.33 (SERPINB), 18q22.1 (CDH7, CDH19), 13q12.3 (FLT1), 13q22.1 (KLF5), 13q22.3 (EDNRB), and 13q34 (COL4A1, COL4A2, F7, F10) were significantly related to biological processes: blood pressure regulation and/or vessel integrity, angiogenesis, coagulation, cell-cell and/or cell-matrix adhesion, dermis integrity, and wound healing (P < 0.05).

CONCLUSIONS

Our findings suggest that gastroschisis may result from the interaction of several chromosomal regions in an additive manner as a pool of candidate genes were identified from critical regions supporting a role for vascular disruption, thrombosis, and mesodermal deficiency in the pathogenesis of gastroschisis.

Maternal Antibodies to Herpes Virus Antigens and Risk of Gastroschisis in Offspring

Gastroschisis risk is highest in offspring of young women and is increasing in prevalence, suggesting that exposures that are increasingly common among younger females may be causal. Some infections by viruses in the herpes family are more common in the earlier childbearing years and have been increasing in prevalence over time. Data from the Finnish Maternity Cohort were linked to Finnish malformation and birth registers (1987-2012) for this study, a nested case-control study of mothers of offspring with gastroschisis and age-matched controls. Maternal antibody responses in early pregnancy (mean gestational age = 11.1 weeks) to Epstein Barr virus (EBV), herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), and cytomegalovirus were measured. Conditional logistic regression models were used to estimate odds ratios (and 95% confidence intervals) for high immunoglobulin reactivity. Odds ratios for high immunoglobulin M (IgM) reactivity to EBV-viral capsid antigen and HSV-1 or HSV-2 (as indicators of recent infection) were 2.16 (95% confidence interval (CI): 0.97, 4.79) and 1.94 (95% CI: 0.74, 5.12), respectively. For higher immunoglobulin G (IgG) reactivity to EBV-viral capsid antigen and HSV-2 IgG, odds ratios were 2.16 (95% CI: 0.82, 5.70) and 2.48 (95% CI: 1.50, 4.10), respectively. Reactivities to HSV-1 IgG, cytomegalovirus IgM, or cytomegalovirus IgG did not appear to increase gastroschisis risk. Primary EBV infection was not associated with gastroschisis, but observed associations with both IgM and IgG reactivities to EBV and HSV suggest that reactivations may be risk factors for it.

Gastroschisis in Uganda: Opportunities for improved survival

PURPOSE

Neonatal mortality from gastroschisis in sub-Saharan Africa is high, while in high-income countries, mortality is less than 5%. The purpose of this study was to describe the maternal and neonatal characteristics of gastroschisis in Uganda, estimate the mortality and elucidate opportunities for intervention.

METHODS

An ethics-approved, prospective cohort study was conducted over a one-year period. All babies presenting with gastroschisis in Mulago Hospital in Kampala, Uganda were enrolled and followed up to 30days. Univariate and descriptive statistical analyses were performed on demographic, maternal, perinatal, and clinical outcome data.

RESULTS

42 babies with gastroschisis presented during the study period. Mortality was 98% (n=41). Maternal characteristics demonstrate a mean maternal age of 21.8 (±3.9) years, 40% (n=15) were primiparous, and fewer than 10% (n=4) of mothers reported a history of alcohol use, and all denied cigarette smoking and NSAID use. Despite 93% (n=39) of mothers receiving prenatal care and 24% (n=10) a prenatal ultrasound, correct prenatal diagnosis was 2% (n=1). Perinatal data show that 81% of deliveries occurred in a health facility. The majority of babies (58%) arrived at Mulago Hospital within 12h of birth, however 52% were breastfeeding, 53% did not have intravenous access and only 19% had adequate bowel protection in place. Four patients (9%) arrived with gangrenous bowel. One patient, the only survivor, had primary closure. Average time to death was 4.8days [range<1 to 14days].

CONCLUSION

The mortality of gastroschisis in Uganda is alarmingly high. Improving prenatal diagnosis and postnatal care of babies in a tertiary center may improve outcome.

Nutritional management and postoperative prognosis of newborns submitted to primary surgical repair of gastroschisis

OBJECTIVE

Gastroschisis is a defect of the abdominal wall, resulting in congenital evisceration and requiring neonatal intensive care, early surgical correction, and parenteral nutrition. This study evaluated newborns with gastroschisis, seeking to associate nutritional characteristics with time of hospital stay.

METHODS

This was a retrospective cohort study of 49 newborns undergoing primary repair of gastroschisis between January 1995 and December 2010. The newborns' characteristics were described with emphasis on nutritional aspects, correlating them with length of hospital stay.

RESULTS

The characteristics that influenced length of hospital stay were: (1) newborn small for gestational age (SGA); (2) use of antibiotics; (3) day of life when enteral feeding was started; (4) day of life when full diet was reached. SGA infants had longer length of hospital stay (24.2%) than other newborns. The length of hospital stay was increased by 2.1% for each additional day taken to introduce enteral feeding. However, slower onset of full enteral feeding acted as a protective factor, decreasing length of stay by 3.6%. The volume of waste drained by the stomach catheter in the 24h prior the start of enteral feeding was not associated with the timing of diet introduction or length of hospital stay.

CONCLUSION

Early start of enteral feeding and small, gradual increase of volume can shorten the use of parenteral nutrition. This management strategy contributes to reduce the incidence of infection and length of hospital stay of newborns with gastroschisis.

Enteral Feeding with Human Milk Decreases Time to Discharge in Infants following Gastroschisis Repair

OBJECTIVE

To assess the effect of enteral feeding with human milk on the time from initiation of feeds to discharge after gastroschisis repair through review of a multi-institutional database.

STUDY DESIGN

Infants who underwent gastroschisis repair between 1997 and 2012 with data recorded in the Pediatrix Medical Group Clinical Data Warehouse were categorized into 4 groups based on the percentage of days fed human milk out of the number of days fed enterally. Cox proportional hazards regression modeling was performed to determine the adjusted effect of human milk on the time from initiation of feeds to discharge.

RESULTS

Among 3082 infants, 659 (21%) were fed human milk on 0% of enteral feeding days, 766 (25%) were fed human milk on 1%-50% of enteral feeding days, 725 (24%) were fed human milk on 51%-99% of enteral feeding days, and 932 (30%) were fed human milk on 100% of enteral feeding days. Following adjustment, being fed human milk on 0% of enteral feeding days was associated with a significantly increased time to discharge compared with being fed human milk on 100% of enteral feeding days (hazard ratio [HR] for discharge per day, 0.46; 95% CI, 0.40-0.52). The same was found for infants fed human milk on 1%-50% of enteral feeding days (HR, 0.37; 95% CI, 0.32-0.41) and for infants fed human milk on 51%-99% of enteral feeding days (HR, 0.51; 95% CI, 0.46-0.57).

CONCLUSION

The use of human milk for enteral feeding of infants following repair of gastroschisis significantly reduces the time to discharge from initiation of feeds.

Limb-body wall defect: experience of a reference service of fetal medicine from Southern Brazil

BACKGROUND

Limb-body wall defect is a rare condition characterized by a combination of large and complex defects of the ventral thorax and abdominal wall with craniofacial and limb anomalies.

METHODS

The aim of this study was to describe the experience of our fetal medicine service, a reference from Southern Brazil, with prenatally diagnosed patients with a limb-body wall defect in a 3 years period. Only patients who fulfilled the criteria suggested by Hunter et al. (2011) were included in the study. Clinical data and results of radiological and cytogenetic evaluation were collected from their medical records.

RESULTS

Our sample was composed of 8 patients. Many of their mothers were younger than 25 years (50%) and in their first pregnancy (62.5%). It is noteworthy that one patient was referred due to suspected anencephaly and another due to a twin pregnancy with an embryonic sac. Craniofacial defects were verified in three patients (37.5%), thoracic/abdominal abnormalities in 6 (75%) and limb defects in eight (100%). Congenital heart defects were observed in five patients (62.5%). One of them presented a previously undescribed complex heart defect.

CONCLUSION

The results disclosed that complementary exams, such as MRI and echocardiography, are important to better define the observed defects. Some of them, such as congenital heart defects, may be more common than previously reported. This definition is essential for the proper management of the pregnancy and genetic counseling of the family. The birth of these children must be planned with caution and for the prognosis a long survival possibility, despite unlikely and rare, must be considered.

A case of choledocholithiasis and intestinal malrotation in an adolescent with repaired gastroschisis

Most infants with repaired gastroschisis develop normally and remain in good health. About 10% of patients with gastroschisis have other malformations. We report a case of choledocholithiasis and intestinal malrotation in an adolescent with repaired gastroschisis. A 17-year-old girl presented with fever, jaundice, and abdominal pain. She had undergone an operation to repair gastroschisis at birth. Physical examination revealed icteric sclera, a tight abdominal wall, and a longitudinal surgical scar at the midline. An abdominal computed tomography scan revealed a round calcifying lesion near the pancreas and a midline-positioned liver and gallbladder. Absence of the retroperitoneal duodenum and the anterior and left-sided position of the superior mesenteric vein compared with the superior mesenteric artery were observed. Results of abarium examination revealed intestinal malrotation. Endoscopic retrograde cholangiopancreatography revealed diffuse dilatation of the biliary trees and a malpositioned gallbladder. A single stone was removed by using a basket. The clinical symptoms improved after the patient underwent endoscopic retrograde cholangiopancreatography.

Anomalies associated with gastroschisis and omphalocele: analysis of 2825 cases from the Texas Birth Defects Registry

BACKGROUND/PURPOSE

The increasing prevalence of abdominal wall defects prompted analysis of anomalies associated with gastroschisis and omphalocele in the Texas Birth Defects Registry (TDBR).

METHODS

Cases of gastroschisis (ICD9 code 756.71), omphalocele (756.70), and/or unspecified anomalies of the abdominal wall (756.79) were obtained from the TDBR after IRB approval and analyzed using Microsoft Access© and Excel© databases.

RESULTS

Analysis began with 2825 cases including 1831 of gastroschisis, 814 of omphalocele, and 180 of unspecified abdominal wall defects plus 9680 associated anomalies that were classified according to system. The overall prevalence of abdominal wall defects among 3,806,299 Texas births from 1999 to 2008 was 7.4 per 10,000 with 4.8 per 10,000 for gastroschisis and 2.1 for omphalocele. After excluding ambiguous cases (8.5% possibly misclassified), anomaly spectra were similar for the two AWD with musculoskeletal (limb contractures or defects), cardiovascular, gastrointestinal, urogenital, and central nervous system defects being most common. Of 1831 cases with gastroschisis, 594 (32%) had associated anomalies compared to 654 (80%) of 814 omphalocele cases.

CONCLUSIONS

Gastroschisis as well as omphalocele has significant associated anomalies that are important to appreciate during pre- and postnatal management.

Amyoplasia involving only the upper limbs or only involving the lower limbs with review of the relevant differential diagnoses

Of individuals with Amyoplasia, 16.8% (94/560) involve only the upper limbs (Upper Limb Amyoplasia-ULA) and 15.2% (85/560) involve only the lower limbs (Lower Limb Amyoplasia-LLA). The accompanying paper deals with other forms of Amyoplasia [Hall et al., 2013] and discusses etiology. An excess of one of monozygotic (MZ) twins is seen in both groups (ULA 4/94 (4.3%), LLA 5/85 (5.9%)), gastrointestinal (GI) abnormalities thought to be of vascular origin (bowel atresia and gastroschisis) (ULA 16/94 (17%), LLA 4/85 (4.7%)), small or partial absence of digits (ULA 6/94 (6.2%), LLA 8/85 (9.4%)), and umbilical cord wrapping around the limbs at birth (ULA 3/94 (3.2%), LLA 7/85 (8.2%)) (severe enough to leave a permanent groove). Pregnancy complications occurred in 42/60 (70%) of ULA and 36/54 (67%) of LLA. Prenatal diagnosis, after ultrasound usage became routine, occurred in only 7/25 (28%) of ULA and 5/12 (12%) of LLA. This series may represent an over estimate of the complications and associations occurring in ULA and LLA. Differential diagnoses separating LLA from the genetic forms of "lower limb only" arthrogryposis and ULA from "upper limb only" genetic forms of arthrogryposis and Erb's palsy is provided.

Intra-abdominal inverted umblical cord in gastroschisis: a unique ultrasound finding

A relatively new surgical technique allows for sutureless closure of a gastroschisis defect. Immediately after birth, a long umbilical cord stump is temporarily inverted into the abdominal cavity and later retracted and used to close the abdominal wall defect. Knowledge of this entity is important since the inverted umbilical cord simulates an intra-abdominal mass on cross-sectional imaging. While this procedure is well described in the surgical literature, the imaging features of inverted umbilical cord have yet to be reported. The case presented here highlights the sonographic imaging findings of the umbilical cord during the intestinal decompression phase of sutureless repair of gastroschisis.

Gastroschisis with ceco-appendicular agenesis: a novel presentation

Gastroschisis is associated with intestinal atresia and malrotation. A few cases have been reported of appendicular agenesis associated with gastroschisis. No previous case has been reported of cecal agenesis with gastroschisis in the literature. As cecal agenesis is a very rare anomaly, its concomitant presentation with gastroschisis is extremely rare. We report a case of gastroschisis associated with ceco-appendicular agenesis. The possible embryological explanation for the presentation is discussed.

Associated malformations and the "hidden mortality" of gastroschisis

BACKGROUND

Little is known about associated anomalies in fetuses with gastroschisis (GS) who experience an "atypical perinatal event," defined as spontaneous abortion, stillbirth, termination, or death within 24 hours of birth.

PURPOSE

This study aims to compare associated malformation rates in an atypical perinatal event cohort vs newborns with GS surviving longer than 24 hours.

METHODS

A national prospective GS database was analyzed for cases with an atypical perinatal event. Associated anomaly rates were compared between this cohort and babies surviving longer than 24 hours.

RESULTS

Twenty-three atypical perinatal events (2 spontaneous abortions, 7 stillbirths, 11 terminations, and 3 deaths within 24 hours) were identified from 529 total GS cases. Autopsies in 14 (61%) of 23 identified at least 1 anomaly (excluding intestinal, patent ductus arteriosus, and undescended testicle) in 11 (78.6%) and a "lethal" anomaly in 4 (36%). The associated anomaly rate in newborns surviving longer than 24 hours was 7.3% (37/506; P < .0001). The anomalies in the atypical perinatal event cohort were musculoskeletal (35%), cardiac, central nervous system, pulmonary, and genitourinary (12% each). Among survivors, the most common anomalies were cardiac (38%), genitourinary (32%), musculoskeletal (16%), and central nervous system (8%).

CONCLUSION

Rates of associated anomalies are significantly higher in fetuses experiencing atypical perinatal events and may represent the "hidden mortality" of GS.

Fetal and neonatal outcome in patients with anterior abdominal wall defects (gastroschisis and omphalocele)

Fetuses with gastroschisis and omphalocele frequently show intrauterine growth restriction (IUGR). The aim of our study was to evaluate the intrauterine course of IUGR and the neonatal outcome in a large patient collective. We retrospectively included all euploid fetuses with gastroschisis and omphalocele between 2001 and 2009 in a single tertiary center. Patients' characteristics, serial ultrasound examinations and neonatal outcomes were evaluated. From 39 fetuses (28 gastroschisis, 11 omphalocele) 61.5% had IUGR <5th percentile and 15.4% had IUGR<10th percentile. The rate of IUGR did not differ significantly between the two groups during pregnancy. Newborns with gastroschisis showed an average weight of 2386 g, and those with omphalocele showed an average weight of 3148 g (P<0.001). Nevertheless, newborns with omphalocele were more frequently eutrophic than those with gastroschisis (88.8% vs. 52.2%, P=0.079). On average, only one surgical intervention was necessary for the definitive repair of the defect (65.5% of the newborns). Children with gastroschisis remained hospitalized nearly twice as long as children with an omphalocele (38 vs. 20 days). IUGR rates during pregnancy did not differ significantly between fetuses with gastroschisis and omphalocele although patients with defects of omphalocele were more frequently eutrophic at birth. Most newborns needed only one operation for definitive surgical treatment. The mean hospitalization time after this intervention was 4 weeks.

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.

Perinatal demography of gastroschisis in North Queensland

AIM

To review the demography of gastroschisis in North Queensland.

METHODS

A retrospective chart review of live born cases of gastroschisis originating in North Queensland from 1988 to 2007.

RESULTS

Fifty-nine cases were identified, giving an overall rate of 3.2 per 10,000 live births. In mothers <20 years old compared with 20-24 and 25-29 it was 12.1, 6.3 and 1.7. Overall, the rate was higher in Indigenous mothers (6.6 vs. 2.6, OR 2.5; 95% CI 1.4-4.5, P= 0.0018). Overall, the rate increased significantly from 0.7 per 10,000 live births in the first 5 years of the study to 4.8 in the last (trend test P= 0.0015), but it increased particularly in mothers <20 years old, from 2.40 in the first 5 years to 19.3 in the last (trend test P= 0.0177). It also rose from 0 to 3.6 in those aged 25-29 (P= 0.0337) but remained stable in other age groups. There was no difference in the outcomes of babies born to Indigenous or non-Indigenous mothers, or in outcomes of babies delivered vaginally or by Caesarean section, or in outcomes of babies from any particular location in North Queensland. There was no significant difference in the average age of Indigenous and non-Indigenous mothers.

CONCLUSION

Gastroschisis is increasing in North Queensland, especially in mothers <20. Overall, the rate in Indigenous mothers is two to three times higher.

Teratogens inducing congenital abdominal wall defects in animal models

Congenital abdominal wall defects are common anomalies which include gastroschisis, omphalocele and umbilical cord hernia. Recent reports indicate that gastroschisis is increasing in prevalence, whereas omphalocele has remained steady, suggesting that environmental factors may play a part in their pathogenesis. The aim of this study is to review animal teratogen studies resulting in abdominal wall defects to investigate their possible causes. Each report was examined not only for the teratogens causing the defects, but also to carefully identify the defect occurring and its correlation with the known clinical anomalies. We found many discrepancies between the nomenclature used by animal teratology investigators and that used by clinicians. We were able to confirm the induction of gastroschisis by 22 teratogens, omphalocele by 9 teratogens and umbilical cord hernia by 8. There is no doubt that environmental factors may be responsible, at least in part, for all three of the clinical abdominal wall defects. Future studies should take care to appreciate the differences between these anomalies and describe them in detail, so that accurate and meaningful conclusions can be obtained.

Commonly encountered surgical problems in the fetus and neonate

Neonatal surgical care requires a current understanding of pre- and postnatal intervention for a myriad of congenital anomalies. This article includes an update of the recent information on commonly encountered fetal and neonatal surgical problems, highlighting specific areas of controversy and challenges in diagnosis. The authors hope that this article is useful for trainees and practitioners involved in any aspect of fetal and neonatal care.