Gastroschisis is caused by the combination of carbon monoxide and protein-zinc deficiencies in mice

Lifestyle and sociodemographic risk factors for gastroschisis: a systematic review and meta-analysis

BACKGROUND

Gastroschisis is strongly associated with young maternal age. This association suggests the need for further investigations on non-genetic risk factors. Identifying these risk factors is a public health priority in order to develop prevention strategies aimed at reducing the prevalence and health consequences in offspring.

OBJECTIVE

To systematically assess and quantitatively synthesise the available epidemiological studies to evaluate the association between non-genetic risk factors and gastroschisis.

METHODS

Literature from PubMed, EMBASE and Scopus was searched for the period 1990-2018. Epidemiological studies reporting risk estimates between lifestyle and sociodemographic risk factors and gastroschisis were included. Two pairs of reviewers independently extracted information on study characteristics following Preferred Reporting Items for Systematic Reviews and Meta-Analyses and MOOSE (Meta-analysis Of Oservational Studies in Epidemiology) guidelines. Relative risk (RR) estimates were calculated across the studies and meta-analysis was performed using random-effects model.

RESULTS

We identified 58 studies. Meta-analyses were conducted on 29 studies. Maternal smoking (RR 1.56, 95% CI 1.40 to 1.74), illicit drug use (RR 2.14, 95% CI 1.48 to 3.07) and alcohol consumption (RR 1.40, 95% CI 1.13 to 1.70) were associated with an increased risk of gastroschisis. A decreased risk among black mothers compared with non-Hispanic white mothers (RR 0.49, 95% CI 0.38 to 0.63) was found. For Hispanic mothers no association was observed.

CONCLUSIONS

Exposure to smoking, illicit drugs and alcohol during pregnancy is associated with an increased risk of gastroschisis. A significantly decreased risk for black mothers was observed. Further epidemiological studies to assess the potential role of other environmental factors are strongly recommended.

PROSPERO REGISTRATION NUMBER

CRD42018104284.

Mode of delivery and outcomes of infants with gastroschisis: a meta-analysis of observational studies

BACKGROUND

There is controversy among the literature for electing caesarean section (CS) delivery for infants with gastroschisis in an attempt to reduce mortality and morbidity.

OBJECTIVE

This meta-analysis investigates whether there is enough evidence to support CS delivery over vaginal delivery.

DATA SOURCES

We conducted our search in April 2017. We searched Cochrane, Medline, Premedline, Embase, CINAHL, GoogleScholar and Web of Science. We also searched conferences for abstracts online. Additional studies were retrieved by reviewing reference lists.

STUDY SELECTION

Observational studies, excluding case series, were eligible if data compared relevant outcomes of infants with gastroschisis in relation to mode of delivery.

DATA EXTRACTION

Relevant information were extracted and assessed the methodological quality of the retrieved records.

RESULTS

Thirty-eight studies were included. Evidence suggested that mode of delivery is not significantly associated with overall mortality (OR 0.82, 95% CI 0.57 to 1.18), primary repair (OR 0.82, 95% CI 0.57 to 1.18), neonatal mortality (OR 1.08, 95% CI 0.54 to 2.15), necrotising enterocolitis, secondary repair, sepsis, short gut syndrome, duration until enteral feeding and duration of hospital stay. Furthermore, sensitivity analyses based on economic status and quality of study showed no significant difference between the impact of mode of delivery for all investigated outcomes.

LIMITATIONS

Due to uncontrolled variables between and within studies, particularly regarding characteristics of delivery and postdelivery care, it is difficult to extract meaningful results from the literature.

CONCLUSIONS

There is insufficient evidence to advocate the use of CS over vaginal delivery for infants with gastroschisis.

Exposure to sub-lethal dose of a combination insecticide during early embryogenesis influences the normal patterning of mesoderm resulting in incomplete closure of ventral body wall of chicks of domestic hen

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Chlorpyrifos and cypermethrin treatment induced developmental anomalies in chicks.

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Protrusion of visceral organs and microphthalmia were the major anomalies observed.

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Treated embryos were conspicuous with incomplete ventral body wall and sternum.

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Altered expression pattern of E-cadherin, Shh, bmp4, Wnt11 and Pitx2 were recorded.

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Impairment of major regulators of development is suspected to induce VBWD.

Pesticide exposure to the non target groups especially during embryonic development has quite often resulted in congenital malformations. A commercially available combination insecticide (Ci, 50% chlorpyrifos and 5% cypermethrin) is known to induce ventral body wall defects (VBWDs) wherein abdominal viscera protrude out of the ventral body wall. Herein, an attempt was made to understand the mechanistic insight into Ci induced VBWDs. For this, before incubation, the chick embryos were dosed with the test chemical and then at different developmental stages of incubation, they were monitored for the changes in the expression of certain genes, which are indispensable for the ventral body wall closure since they regulate the cell fate, proliferation and survival. Concurrently, histopathological changes during the embryonic development were examined to corroborate the above observations. The results of mRNA profiling revealed a significant downregulation of Shh on day 4 and upregulation on day 10, while bmp4, Pitx2, E-cadherin, Wnt11, Wnt6, Pxn, MyoD1, Caspase-3, AHR, Cyp3A4, showed a significant upregulation on day 4 and/or on day 10. N-cadherin, fgf8, bmp1 showed no significant changes. The possible means by which these skewed expression patterns of regulatory molecules culminated into the VBWD are discussed.

An evaluation of nutritional and vasoactive stimulants as risk factors for gastroschisis: a pilot study

OBJECTIVE

The objective of this study is to evaluate poor maternal nutrition, environmental exposures and vasoactive stimulants as potential risk factors for gastroschisis.

METHODS

A case-control study was conducted among singleton pregnancies diagnosed in a tertiary teaching hospital in a 22-month period. Cases of gastroschisis were matched to controls at the time of diagnosis by race and maternal age. Demographics, periconceptual exposures, nutritional biomarkers, and illicit drug hair analysis were evaluated. Analyses were performed using conditional logistic regression.

RESULTS

Thirty gastroschisis cases and 76 controls were studied with no associations observed for illicit drug use or serum levels of ferritin, iron, B6, B12, folate, or zinc. Neither prescription medication nor over the counter mediation use differed between cases and controls. Following adjustment for insurance, education, low BMI, and nulliparity, mothers of gastroschisis cases had an increased odds of alcohol use 1 month prior and/or during early pregnancy compared with controls, with adjusted odds ratio (OR) 3.19 (95% CI 1.01-11.61).

CONCLUSIONS

Our findings suggest that further investigation of vasoactive stimulants such as alcohol is warranted in the search to identify risk factors for gastroschisis.

Uncertainty in maternal exposures to ambient PM2.5 and benzene during pregnancy: Sensitivity to exposure estimation decisions

We investigate uncertainty in estimates of pregnant women's exposure to ambient PM2.5 and benzene derived from central-site monitoring data. Through a study of live births in Florida during 2000-2009, we discuss the selection of spatial and temporal scales of analysis, limiting distances, and aggregation method. We estimate exposure concentrations and classify exposure for a range of alternatives, and compare impacts. Estimated exposure concentrations were most sensitive to the temporal scale of analysis for PM2.5, with similar sensitivity to spatial scale for benzene. Using 1-12 versus 3-8 weeks of gestational age as the exposure window resulted in reclassification of exposure by at least one quartile for up to 37% of mothers for PM2.5 and 27% for benzene. The largest mean absolute differences in concentration resulting from any decision were 0.78 µg/m(3) and 0.44 ppbC, respectively. No bias toward systematically higher or lower estimates was found between choices for any decision.

Maternal nutrition and gastroschisis: findings from the National Birth Defects Prevention Study

OBJECTIVE

Gastroschisis is increasing in many countries, especially among young women. Because young women may have inadequate nutrition, we assessed the relationship between individual nutrients and the risk for gastroschisis.

STUDY DESIGN

We analyzed data from the National Birth Defects Prevention Study, a population-based case-control study. Cases were ascertained from 10 birth defect surveillance systems. Controls were randomly selected from birth certificates or hospital records. Nutrient intake was estimated for the year prior to conception from maternal interviews based on a 58-item food frequency questionnaire and cereal consumption reported. A total of 694 cases and 6157 controls were available for analysis.

RESULTS

Reported intake of individual nutrients did not substantially affect the risk for gastroschisis. Stratification by maternal age, preconception body mass index, folic acid-containing supplements, or energy intake (kilocalories) did not alter risk estimates.

CONCLUSION

This study does not support an increased risk for gastroschisis with decreasing tertiles of individual nutrients.

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.

Maternal periconceptional illicit drug use and the risk of congenital malformations

BACKGROUND

In 2004, the Survey on Drug Use and Health showed that 5% of American women reported use of an illicit drug during pregnancy. The results of studies determining the association between periconceptional illicit drug use and birth defects have been inconsistent.

METHODS

We analyzed data from the National Birth Defects Prevention Study, a case-control study of major birth defects, and assessed all birth defects categories in which there were at least 250 interviewed case mothers. We included 10,241 infants with major congenital malformations (case infants) and 4,967 infants without major congenital malformations (control infants) born between 1997 and 2003 for whom there was a completed maternal interview with detailed information on prenatal illicit drug use and potential confounders. We used multivariable logistic regression to estimate the associations between cannabis, cocaine, and stimulant use in the month before pregnancy or during the first trimester (periconceptional period) and the occurrence of selected birth defects.

RESULTS

In the periconceptional period, 5% of the 15,208 mothers reported any use of illicit drugs. We did not find associations between illicit drug use and most of the 20 eligible categories of congenital malformations. Periconceptional cannabis use seemed to be associated with an increased risk of anencephaly (adjusted odds ratio = 1.7; 95% confidence interval = 0.9-3.4), whereas cocaine use in the periconceptional period was associated with the risk of cleft palate (2.5; 1.1-5.4).

CONCLUSIONS

There were very few suggestions of positive associations between periconceptional illicit drug use and the 20 birth defects categories.

A case control population-based study investigating smoking as a risk factor for gastroschisis in Utah, 1997-2005

BACKGROUND

Smoking in pregnancy increases the risk for many different adverse pregnancy outcomes, including birth defects. Gastroschisis, a birth defect most commonly associated with young maternal age has been associated with smoking, but findings are inconsistent. We assessed whether smoking increases the risk for gastroschisis using population-based data from Utah.

METHODS

Gastroschisis cases (n = 189) were identified from the Utah Birth Defect Network and all live births without birth defects (n = 423,499) occurring in Utah from January 1, 1997 through December 31, 2005 served as controls. Exposure data were derived from birth certificates and fetal death certificates and, for terminated pregnancies, the Utah Birth Defect Network.

RESULTS

Women who smoked during the first trimester of pregnancy had an increased risk of gastroschisis (OR 1.6; 95% CI: 1.1, 2.3) after adjusting for maternal age and preconception BMI. Discordance between birth certificate data and data from structured interviews increased exposure prevalence from 16.9 to 22.2% for case mothers and 7.4 to 13.2% for control mothers. Accounting for this misclassification, the crude OR decreased by 24%, 1.9 (1.3, 2.7).

CONCLUSIONS

Though first trimester cigarette smoking was reported on birth certificates by more mothers of gastroschisis cases than controls, adjustment for confounders (maternal age and preconception BMI) and smoking misclassification suggests the association is weak. Despite a decrease in smoking prevalence among all women of childbearing years in Utah between 1997 and 2005, the prevalence of gastroschisis has not followed a similar trend.

Impact of maternal substance abuse and smoking on children with gastroschisis

BACKGROUND/PURPOSE

Conflicting information exists regarding the effects of maternal substance abuse on gastroschisis. The objectives of this study are to determine if maternal smoking is associated with an increased risk of gastroschisis and whether substance abuse is associated with the severity of gastroschisis.

METHODS

The Canadian Pediatric Surgery Network (CAPSNET) database was evaluated for associations between maternal substance abuse and the severity of the gastroschisis. We also compared smoking rates from this group to overall Canadian maternal smoking rates.

RESULTS

One hundred fourteen cases of gastroschisis acquired over 18 months were evaluated. After adjusting for covariates, illicit drug use was associated with bowel necrosis (OR, 9.4; 95% CI,1.3-70) and marijuana use with matting of the intestines (OR, 4.0; 95% CI, 1.0-16). Functional outcomes assessment revealed that slower initiation of enteral feeds was associated with maternal smoking (OR, 3.8; 95% CI, 1.4-10). The overall maternal smoking rate in this cohort (30.7%) was significantly higher than the known Canadian rate (13.4%). This may be accounted for by the considerably higher smoking rate of mothers 20 to 24 years of age in our cohort (48.9%).

CONCLUSIONS

Substance abuse and smoking are associated with a greater severity of gastroschisis in terms of both the degree of intestinal injury and functional outcomes. High smoking rates among young mothers may be putting children with gastroschisis at risk for poor outcomes.

Bovine meroanencephaly and gastroschisis: a macro and microscopic study

Congenital malformations correspond to one of the main causes of embryonic loss during the gestational process. They result from interaction of several factors such as multifactor heredity, chromosomal and genetic alterations and environmental agents; however, unknown aetiology also can be present. In this article, we have used 10 embryos, from a frigorific area of Dracena, SP, Brazil, which were fixed in Bouin solution for a macro- and micro-scopic description. We could verify the presence of an encephalic tissue mass on the embryo's dorsal cranial area, resulting from the non-formation of part of the cranial cap and from the non-closing of cephalic neuropore and consequent neuroepithelial cells disorganization. In the abdominal area, the embryos did not show the complete fusion of the body lateral pleats during the abdominal wall formation, and the liver extruded into the amniotic cavity without involvement of the intestine.

Development of gastroschisis: review of hypotheses, a novel hypothesis, and implications for research

Gastroschisis, a ventral body wall defect, is a continuing challenge and concern to researchers, clinicians, and epidemiologists seeking to identify its cause(s) and pathogenesis. Concern has been renewed in recent years because, unlike most other birth defects, rates of gastroschisis are reportedly increasing in many developed and developing countries. No tenable explanation or specific causes have been identified for this trend. Rates of gastroschisis are particularly high among pregnancies of very young women. Such an intriguing association, not observed to this degree with other birth defects, may afford clues to the defect's cause. Understanding the causes of gastroschisis may provide insight to the defect's origin. In pursuing such causal studies, it would be helpful to understand the embryogenesis of gastroschisis. To date, four main embryologic hypotheses have been proposed: (1) Failure of mesoderm to form in the body wall; (2) Rupture of the amnion around the umbilical ring with subsequent herniation of bowel; (3) Abnormal involution of the right umbilical vein leading to weakening of the body wall and gut herniation; and (4) Disruption of the right vitelline (yolk sac) artery with subsequent body wall damage and gut herniation. Although based on embryological phenomena, these hypotheses do not provide an adequate explanation for how gastroschisis would occur. Therefore, we propose an alternative hypothesis, based on well described embryonic events. Specifically, we propose that abnormal folding of the body wall results in a ventral body wall defect through which the gut herniates, leading to the clinical presentation of gastroschisis. This hypothesis potentially explains the origin of gastroschisis as well as that of other developmental defects of the ventral wall.

Omphalocele induction in the chick embryo by administration of cadmium

BACKGROUND

Ventral body wall (VBW) defects occur in 1:2000 live births. We examined the association of VBW defect with somite abnormality and lordosis in the chick using in vitro and in ovo methods.

METHODS

Explanted chick embryos were treated at 60 hours with 50 microL sodium acetate or 0.001% cadmium acetate solution to produce VBW defects. Mortality and abnormality rates were assessed. A further cohort of chicks was treated in ovo by dropping 50 microL 0.001% to 0.01% cadmium acetate onto the embryo and allowing development to 16.5 days for further assessment of the defect and skeletal staining with alcian blue and alizarin red.

RESULTS

Cadmium treatment at 24 hours induced VBW defects in chicks treated in both shell-less culture and in ovo. Material herniating through the VBW defects was covered by a membrane in all fresh specimens. Membrane removal revealed large defects containing liver and bowel. These criteria clearly indicate that the defect observed is an omphalocele. Affected embryos had reduced somite numbers within 24 hours. Chicks exhibiting exomphalos at 16.5 days invariably had lumbosacral lordosis.

CONCLUSIONS

The cadmium-treated chick embryo is a reliable model for exomphalos. A positive association was found between exomphalos and lumbar lordosis in the chick.

Interaction between maternal smoking and malnutrition in infant risk of gastroschisis

BACKGROUND

Gastroschisis is a severe birth defect characterized by a tear in the infant's abdominal wall. Young mothers have the highest risk of having an infant with gastroschisis. In an animal model, the defect resulted from exposure of pregnant mice to carbon monoxide (CO) in combination with a low protein and low zinc diet.

METHODS

We evaluated this model in a study of 55 infants with gastroschisis and 94 age-matched controls that included maternal interview with a food frequency questionnaire. Smoking cigarettes (> or = 1 pack/day) or marijuana (more than once) 3 months prior to pregnancy indicated CO exposure. Low protein or zinc intake and a low body mass index (BMI) indicated maternal malnutrition.

RESULTS

When assessed separately, high CO, low protein, low zinc, and low BMI were each significantly associated with an increased risk of gastroschisis. Although we observed significant CO-BMI and CO-zinc interactions after adjusting for income, only a combination of high CO exposure and low BMI yielded a synergistic adverse effect. Compared to the low risk of having an infant with gastroschisis for mothers who did not have low BMI and did not smoke, the risk of having an infant with gastroschisis was 16.3 times (95% CI, 2.49-113.4) higher for mothers who did not have low BMI but smoked, and 19.7 times (95% CI, 4.33-89.6) higher for mothers who did not smoke but had low BMI. However, the risk was 26.5 times (95% CI, 7.85-89.4) higher for mothers who had low BMI and smoked.

CONCLUSIONS

Our results suggest that young mothers are at increased risk of having an infant with gastroschisis if they smoke and are also malnourished.

Selected gene polymorphisms and their interaction with maternal smoking, as risk factors for gastroschisis

BACKGROUND

Gastroschisis is a severe birth defect in which the infant is born with a portion of the intestines extruding through a small tear in the abdominal wall, usually to the right of the umbilical cord. Its etiology is unknown, but the prevailing hypothesis is that it results from a vascular accident at the time of involution of the right umbilical vein or of the development of the superior mesenteric artery.

METHODS

In a case-control study of 57 cases of gastroschisis and 506 controls, we tested DNA for polymorphisms of 32 genes representing enzymes involved in angiogenesis, blood vessel integrity, inflammation, wound repair, and dermal or epidermal strength.

RESULTS

In logistic regression, controlling for maternal ethnicity, and using the homozygote wild-type as referent, the following gene polymorphisms were associated with an increased risk for a gastroschisis for heterozygotes: ICAM1 gly241arg (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.1 -3.4); NOS3 glu298asp (OR, 1.9; 95% CI, 1.1-3.4); NPPA 2238T > C (OR, 1.9; 95% CI, 1.0-3.4); and ADD1 gly460trp (OR, 1.5; 95% CI, 0.8-2.8). Additionally, for the NPPA and ADD1 single-nucleotide polymorphisms (SNPs), the homozygote variants had a significantly higher risk than the heterozygotes (OR, 7.5; 95% CI, 1.7-33.5 and OR, 4.9; 95% CI, 1.9-12.9, respectively). Three SNPs showed a strong interaction with maternal smoking. The risk for smokers with 1 or 2 variant alleles compared to nonsmokers with the wild-type allele were: NOS3 (OR, 5.2; 95% CI, 2.4-11.4); ICAM1 (OR, 5.2; 95% CI, 2.1-12.7); and NPPA (OR, 6.4; 95% CI, 2.8-14.6).

CONCLUSIONS

These results support the hypothesis of a vascular compromise as part of a multifactorial etiology of gastroschisis involving both genes and environmental factors.

Interaction of maternal protein and carbon monoxide on pup mortality in mice: implications for global infant mortality

BACKGROUND

The United States Surgeon General declared 2005 as the "Year of Healthy Child." To improve the health of all children, we need to start before pregnancy, with their mothers. Unfortunately, protein deficiency in the diets of poor pregnant mothers in developing countries is widespread. Carbon monoxide (CO) pollution is serious public health problem in developed and developing countries.

METHODS

A two-way factorial experimental design was used. Mice were maintained on 27%, 16%, 8%, or 4% protein diets. Dams were exposed to 0 ppm (control), 65 ppm, or 125 ppm CO in air, in environmental chambers for 6 hr/day during the first 2 weeks of pregnancy. Controls were also subjected to environmental chamber conditions. Food and water were available at all times. Animals were allowed to deliver, and data on pup mortality was recorded.

RESULTS

Litter size was not affected by CO exposure, but was directly related to the dietary protein levels. Pup weight was inversely related to the CO exposure level, and directly related to the dietary protein levels. Pup mortality on date of birth was increased by CO exposure and was inversely related to the dietary protein levels. Pup mortality at 1 week of age was increased by CO exposure and 55% of all pups died in 125 ppm CO exposed group. Pup mortality at 1 week of age was inversely related to dietary protein levels. All pups in the 4% dietary protein and in all concentrations of CO died. All pups in the 8% protein group and in all CO concentrations died except in 125 ppm CO group. Pup mortality in the 16% dietary protein group ranged from 14.8% in 0 ppm to 36.8% in 65 ppm CO groups. Pup mortality in the 27% dietary protein group ranged from 14.3% in the 0 ppm to 41.1% in the 125 ppm CO groups.

CONCLUSIONS

DATA suggest that protein deficiency and CO exposure enhance pup mortality. The protein and CO also interact to increase pup mortality in 16% and 27% protein groups. Carbon monoxide exposure, along with protein deficiency during gestation, may be contributing factors for high rates of infant mortality in developing countries. The results of the study also suggest that un-vented combustion for heating and cooking, ambient pollution, and biomass smoke may have a major impact on the health of children worldwide; and may explain the causes of high infant mortality in poor countries and some sections of the United States population.