Non-genetic risk factors for gastroschisis

Adverse event reports after tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccines in pregnant women

OBJECTIVE

We sought to characterize reports to the Vaccine Adverse Event Reporting System (VAERS) of pregnant women who received tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap).

STUDY DESIGN

We searched VAERS for reports of pregnant women who received Tdap from Jan. 1, 2005, through June 30, 2010. We conducted a clinical review of reports and available medical records.

RESULTS

We identified 132 reports of Tdap administered to pregnant women; 55 (42%) described no adverse event (AE). No maternal or infant deaths were reported. The most frequent pregnancy-specific AE was spontaneous abortion in 22 (16.7%) reports. Injection site reactions were the most frequent non-pregnancy-specific AE found in 6 (4.5%) reports. One report with a major congenital anomaly (gastroschisis) was identified.

CONCLUSION

During a time when Tdap was not routinely recommended in pregnancy, review of reports to VAERS in pregnant women after Tdap did not identify any concerning patterns in maternal, infant, or fetal outcomes.

Preparing for influenza after 2009 H1N1: special considerations for pregnant women and newborns

Pregnant women and their newborn infants are at increased risk for influenza-associated complications, based on data from seasonal influenza and influenza pandemics. The Centers for Disease Control and Prevention (CDC) developed public health recommendations for these populations in response to the 2009 H1N1 pandemic. A review of these recommendations and information that was collected during the pandemic is needed to prepare for future influenza seasons and pandemics. The CDC convened a meeting entitled "Pandemic Influenza Revisited: Special Considerations for Pregnant Women and Newborns" on August 12-13, 2010, to gain input from experts and key partners on 4 main topics: antiviral prophylaxis and therapy, vaccine use, intrapartum/newborn (including infection control) issues, and nonpharmaceutical interventions and health care planning. Challenges to communicating recommendations regarding influenza to pregnant women and their health care providers were also discussed. After careful consideration of the available information and individual expert input, the CDC updated its recommendations for these populations for future influenza seasons and pandemics.

Neonatal abdominal wall defects

Gastroschisis and omphalocele are the two most common congenital abdominal wall defects. Both are frequently detected prenatally due to routine maternal serum screening and fetal ultrasound. Prenatal diagnosis may influence timing, mode and location of delivery. Prognosis for gastroschisis is primarily determined by the degree of bowel injury, whereas prognosis for omphalocele is related to the number and severity of associated anomalies. The surgical management of both conditions consists of closure of the abdominal wall defect, while minimizing the risk of injury to the abdominal viscera either through direct trauma or due to increased intra-abdominal pressure. Options include primary closure or a variety of staged approaches. Long-term outcome is favorable in most cases; however, significant associated anomalies (in the case of omphalocele) or intestinal dysfunction (in the case of gastroschisis) may result in morbidity and mortality.

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.

Rising prevalence of gastroschisis in Washington State

The aim of this study was to assess gastroschisis prevalence in Washington (WA) State in relation to putative risk factors. Gastroschisis prevalence was calculated from the WA State birth cohort during 1987-2006 using an administrative database with birth certificate data linked with hospital discharge records and the ICD-9 procedure code 54.71, which specifies gastroschisis repair. Poisson regression analysis was used to evaluate time trends while adjusting for risk factors. Birth year was included as a linear term. Maternal age, smoking, race, residence in urban versus rural area, geographic region (eastern versus western Washington), paternal age, and infant gender were included as categorical factors. Prevalence ratios were adjusted for birth year and all of the preceding factors. Two hundred and eighty-two infants with gastroschisis were identified. In the adjusted analysis, the prevalence ratio for gastroschisis was 1.1 per year (95% CI 1.08-1.13), indicating an average 10% increase per birth year. Teen mothers were at a higher risk compared to mothers≥25 yr old (adjusted rate ratio [aRR] 8.02; 95% CI 5.30-12.13), as were teen fathers (aRR 2.35; 95% CI 1.48-3.74) compared to fathers≥25 years old. Maternal smoking was associated with a higher risk compared to those who were nonsmokers (aRR 1.58; 95% CI 1.19-2.09). Black mothers had a lower risk compared with white mothers. There was no association with geographic classification of mother's residence. Gastroschisis prevalence has increased in WA, particularly in teen mothers and in smokers. This is not explained by a rise in teenage pregnancies or maternal smoking. Further investigation of factors specific to teenage lifestyle is warranted.

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.

Pathogenic implications of remnant vitelline structures in gastroschisis

PURPOSE

The pathogenesis of gastroschisis is unknown. It may be helpful in understanding its pathogenesis to know the structural relationships among umbilical components including umbilical vessels, urachus, and vitelline structures, and thus, the authors investigated the remnants of vitelline structures in a series of cases of gastroschisis.

METHODS

Medical records of 41 cases with gastroschisis treated in our institute from 1979 to 2009 were retrospectively reviewed.

RESULTS

Paraumbilical bands, possible remnants of vitelline structures, were observed in 4 cases (9.8%). All 4 bands were attached to the skin edge of the abdominal defect without incorporation into the umbilical cord. The band ended at the mesentery in 3 cases and at the antimesenteric site of the ileum in the remaining case. Histologic findings showed fibrous tissues in all cases. One was possibly associated with the development of colonic atresia. Another was noticed after silo reduction when herniated bowels became strangulated by the band. The other 2 cases were uncomplicated.

CONCLUSIONS

Our findings may support the recently proposed hypothesis that the developmental failure of the yolk sac and related vitelline structures to merge with or to be incorporated into the umbilical stalk might be associated with the pathogenesis of the abdominal wall defect in gastroschisis. Paraumbilical bands derived from vitelline structures may possibly cause intestinal ischemia prenatally or postnatally.

The embryologic origin of ventral body wall defects

Ventral body wall defects include ectopia cordis, bladder exstrophy, and the abdominal wall malformations gastroschisis and omphalocele. The etiology of ectopia cordis, gastroschisis, and bladder exstrophy is not known, but they may be linked to abnormalities in the lateral body wall folds responsible for closing the thoracic, abdominal, and pelvic portions of the ventral body wall. These folds form in the fourth week (postfertilization) of development as a combination of the parietal layer of lateral plate mesoderm and overlying ectoderm and must move ventrally to meet in the midline. There are differential rates of cell proliferation in the folds and asymmetries in their movement that may be involved in teratogenic effects of toxic factors. Also, the fusion process between the folds is complex, involving cell-to-cell adhesion, cell migration, and cell reorganization and all of these phenomena may be targets for disruption, leading to malformations. In this regard, closure of the ventral body wall is likened to neural tube closure and involves similar processes. It also encompasses a similar time frame during development, such that most neural tube and ventral body wall defects have their origins during the fourth week of development. Omphalocele is a separate entity whose etiology is known. This defect is attributed to a failure of gut loops to return to the body cavity after their normal physiological herniation into the umbilical cord from the 6th to 10th week of development. Thus, the origin of this defect is completely different from that of the ventral body wall malformations.

Hypothesis: could Epstein-Barr virus play a role in the development of gastroschisis?

BACKGROUND

The strong inverse association between maternal age and risk of gastroschisis in offspring has spurred many investigators to hypothesize that behaviors among younger females are the cause. Examples include cigarette smoking, illicit drugs, genitourinary infections, and sexually transmitted diseases, each of which has been reported to be associated with gastroschisis. Although these exposures are more common in young women, recent studies have shown that cigarette smoking, genitourinary infections, and sexually transmitted diseases are most strongly associated with gastroschisis in older women. There is both anecdotal and published evidence showing that gastroschisis sometimes (but not always) occurs in clusters, raising the possibility that an infectious agent might be involved in its pathogenesis.

RESULTS

One such agent whose epidemiologic characteristics parallel those of gastroschisis is Epstein-Barr virus (EBV). Primary EBV infection in early childhood has been decreasing over time, leaving a greater proportion of adolescents at risk, as reflected by increased rates of infectious mononucleosis over time. During the childbearing years, risk of primary EBV infection decreases dramatically, as does risk of gastroschisis. The stronger risks of gastroschisis associated with cigarette smoking, genitourinary infections, and sexually transmitted diseases in older women might be explained by EBV reactivation resulting from multiple challenges to immune response such as pregnancy, age, toxic exposures, and genitourinary and sexually transmitted infections.

CONCLUSION

EBV and other herpes viruses should be added to the research agenda for gastroschisis.

Association of paternal age and risk for major congenital anomalies from the National Birth Defects Prevention Study, 1997 to 2004

PURPOSE

The objective of this study was to examine the associations between paternal age and birth defects of unknown etiologies while carefully controlling for maternal age.

METHODS

By using 1997 to 2004 data from the National Birth Defects Prevention Study, we fit logistic regression models with paternal and maternal age as continuous variables while adjusting for demographic and other factors.

RESULTS

Elevated odds ratios (ORs) for each year increase in paternal age were found for cleft palate (OR. 1.02, 95% confidence interval [95% CI], 1.00-1.04), diaphragmatic hernia (OR, 1.04; 95% CI, 1.02-1.06), right ventricular outflow tract obstruction (OR, 1.03; 95% CI, 1.01-1.04), and pulmonary valve stenosis (OR, 1.02, 95% CI, 1.01-1.04). At younger paternal ages, each year increase in paternal age correlated with increased odds of having offspring with encephalocele, cataract, esophageal atresia, anomalous pulmonary venous return, and coarctation of the aorta, but these increased odds were not observed at older paternal ages. The effect of paternal age was modified by maternal age for gastroschisis, omphalocele, spina bifida, all orofacial clefts, and septal heart defects.

CONCLUSIONS

Our findings suggest that paternal age may be a risk factor for some multifactorial birth defects.

Surgical management of gastroschisis in North Queensland from 1988 to 2007

AIM

To review outcomes of gastroschises originating in North Queensland and repaired in the neonatal centre in Townsville from 1988-2007, and compare these outcomes with published data from other centres.

METHODS

A retrospective chart review of outcomes after primary operative repair (POR) with wound closure in fascial layers in the theatre, primary non-operative repair (PNOR) with apposition of the umbilical cord and adhesive dressing in the ward, secondary repair (SR) after a silo, and complex repair (CR) of cases with obstruction, perforation or atresiae. Epidemiological data of babies originating in North Queensland but managed in Brisbane were secured from Mater Mothers' Hospital and the Royal Hospital for Children.

RESULTS

Fifty cases were treated in Townsville: 16 by PNOR, 22 by POR, 6 by SR and 6 by CR. Outcomes of uncomplicated cases treated by PNOR, POR and SR were similar. Outcomes of complicated cases after CR were significantly worse. No significant differences were found between PNOR in Townsvillle and published outcomes after SR from four overseas units. No differences were detected in outcomes of inborn and outborn babies, those delivered by vaginal or caesarean birth or between indigenous and non-indigenous babies. Three (6%) died. Gastroschisis is increasing in North Queensland, particularly in younger mothers. The incidence is 2-3 times higher in indigenous mothers.

CONCLUSION

No significant differences were found between PNOR and other techniques for uncomplicated cases. PNOR avoids the use of theatre and staff, reducing delay and cost, and the need to transport a sick baby.

Pandemic influenza and pregnant women: summary of a meeting of experts

Pandemic Influenza: Special Considerations for Pregnant Women was a meeting convened by the Centers for Disease Control and Prevention in 2008 to obtain input from experts and key partners regarding clinical management of pregnant women and related public health actions to be taken during a pandemic. Meeting goals were to discuss issues specific to pregnant women, identify gaps in knowledge, and develop a public health approach for pregnant women in the event of a pandemic. The meeting focused on 4 main topics: prophylaxis and treatment with influenza antiviral and other medications, vaccine use, nonpharmaceutical interventions and health care planning, and communications. Participants reviewed the available evidence to guide action in each of these areas and identified areas of critical needs for future research.

Genetic testing in other GI diseases

Gastrointestinal development is a complex process comprising folding of the endodermal layer to form the primitive gut tube, cell differentiation along its anteroposterior axis, the budding of the various organ primordia and development of derivative organs like the liver and pancreas and the colonisation of the gut with neuronal precursors. Genetic factors are increasingly recognised as playing a significant role in the disturbance of this developmental process which underlies congenital malformations and gastrointestinal disorders. Furthermore, genetic variation and its interaction with environmental influences play an important role in the pathogenesis of functional gastrointestinal disorders. In this review, we discuss the contribution of genetic variants, ranging from highly penetrant mutations and chromosomal abnormalities to genetic polymorphisms, to the pathogenesis of a number of structural and functional gastrointestinal disorders.

Risk factors for gastroschisis

Genitourinary infection in early pregnancy can be added to the existing list