Omphalocele and gastroschisis: a collaborative study of five Italian congenital malformation registries

Gastroschisis prevalence patterns in 27 surveillance programs from 24 countries, International Clearinghouse for Birth Defects Surveillance and Research, 1980-2017

BACKGROUND

Gastroschisis is a serious birth defect with midgut prolapse into the amniotic cavity. The objectives of this study were to evaluate the prevalence and time trends of gastroschisis among programs in the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR), focusing on regional variations and maternal age changes in the population.

METHODS

We analyzed data on births from 1980 to 2017 from 27 ICBDSR member programs, representing 24 countries and three regions (Europe+ (includes Iran) , Latin America, North America). Cases were identified using diagnostic codes (i.e., 756.7, 756.71, or Q79.3). We excluded cases of amniotic band syndrome, limb-body wall defect, and ruptured omphalocele. Programs provided annual counts for gastroschisis cases (live births, stillbirths, and legally permitted pregnancy terminations for fetal anomalies) and source population (live births, stillbirths), by maternal age.

RESULTS

Overall, gastroschisis occurred in 1 of every 3268 births (3.06 per 10,000 births; 95% confidence intervals [CI]: 3.01, 3.11), with marked regional variation. European+ prevalence was 1.49 (95%CI: 1.44, 1.55), Latin American 3.80 (95%CI: 3.69, 3.92) and North American 4.32 (95%CI: 4.22, 4.42). A statistically significant increasing time trend was observed among six European+ , four Latin American, and four North American programs. Women <20 years of age had the highest prevalence in all programs except the Slovak Republic.

CONCLUSIONS

Gastroschisis prevalence increased over time in 61% of participating programs, and the highest increase in prevalence was observed among the youngest women. Additional inquiry will help to assess the impact of the changing maternal age proportions in the birth population on gastroschisis prevalence.

A rare case of limb body wall complex

Limb body wall complex (LBWC) is a complex and rare poly-malformative syndrome. We report a case of this syndrome diagnosed antenatally in a 37-year-old primiparous woman, by a first obstetrical ultrasound performed at 22 weeks of amenorrhea and one day. After termination of pregnancy, macroscopic examination revealed a male newborn with all the diagnostic criteria of LBWC.

Embryology of the Abdominal Wall and Associated Malformations—A Review

In humans, the incidence of congenital defects of the intraembryonic celom and its associated structures has increased over recent decades. Surgical treatment of abdominal and diaphragmatic malformations resulting in congenital hernia requires deep knowledge of ventral body closure and the separation of the primary body cavities during embryogenesis. The correct development of both structures requires the coordinated and fine-tuned synergy of different anlagen, including a set of molecules governing those processes. They have mainly been investigated in a range of vertebrate species (e.g., mouse, birds, and fish), but studies of embryogenesis in humans are rather rare because samples are seldom available. Therefore, we have to deal with a large body of conflicting data concerning the formation of the abdominal wall and the etiology of diaphragmatic defects. This review summarizes the current state of knowledge and focuses on the histological and molecular events leading to the establishment of the abdominal and thoracic cavities in several vertebrate species. In chronological order, we start with the onset of gastrulation, continue with the establishment of the three-dimensional body shape, and end with the partition of body cavities. We also discuss well-known human etiologies.

Application of quantitative fluorescent polymerase chain reaction analysis for the rapid confirmation of trisomy 13 of maternal origin in a pregnancy with fetal holoprosencephaly, cyclopia, polydactyly, omphalocele and cell culture failure

OBJECTIVE

We present the application of quantitative fluorescent polymerase chain reaction (QF-PCR) for the rapid confirmation of trisomy 13 of maternal origin in a pregnancy with fetal holoprosencephaly (HPE), cyclopia, polydactyly, omphalocele and cell culture failure.

CASE REPORT

A 21-year-old, gravida 2, para 0, woman was referred for termination of the pregnancy at 17 weeks of gestation because of the abnormal ultrasound finding of alobar HPE. The pregnancy was subsequently terminated, and a 118-g malformed male fetus was delivered with cyclopia, bilateral postaxial polydactyly of the hands and ruptured omphalocele. Postmortem cell culture of the placental tissue and umbilical cord was not successful. The parental karyotypes were normal. QF-PCR analysis using the polymorphic DNA markers of D13S1810, D13S790 and D13S251 on the DNA extracted from placenta, umbilical cord and parental bloods showed trisomy 13 of maternal origin.

CONCLUSION

Perinatal diagnosis of concomitant HPE, polydactyly and omphalocele should raise a suspicion of fetal trisomy 13. QF-PCR analysis is useful for rapid confirmation of trisomy 13 and the parental origin especially under the circumstance of cell culture failure, and the information acquired is very useful for genetic counseling of the parents.

Co-occurring non-omphalocele and non-gastroschisis anomalies among cases with congenital omphalocele and gastroschisis

The pathogenesis of omphalocele and gastroschisis is not obvious. Their etiology is disputed. The prevalence and the types of anomalies co-occurring with omphalocele and gastroschisis are variable in the different series published. The aim of this study was to estimate the frequency and the types of co-occurring anomalies in cases with gastroschisis and omphalocele. This study was performed in a well-described population of 387,067 consecutive births between 1979 and 2007. Hundred-one cases with omphalocele were registered (2.61 per 10,000), 75 (74.3%) had co-occurring anomalies comprising chromosomal anomalies (28 cases, 27.7%, including 18 trisomy 18), non-chromosomal syndromes (16 cases, 15.8%, including 3 cases with Beckwith-Wiedemann syndrome, 2 cases with the OEIS sequence, and one case with the Pentalogy of Cantrell complex), and 31 cases, 30.7% with MCA (multiple congenital anomalies). The most common MCA were musculoskeletal (23.5%), urogenital (20.4%), cardiovascular (15.1%), and central nervous (9.1%). Seventy-one cases of gastroschisis were ascertained (1.83 per 10,000). However, the prevalence increased during the study period. The frequency was highest in the mothers 15-19 years old. Sixteen out of the 71 cases with gastroschisis, (22.5%) had co-occurring anomalies including 11 cases of MCA and 5 cases with syndromes. To conclude, the frequency and the types of anomalies co-occurring with omphalocele and gastroschisis are peculiar. Therefore, cases with gastroschisis and omphalocele need to be screened for co-occurring anomalies.

Abdominal Wall Defects-Current Treatments

Gastroschisis and omphalocele reflect the two most common abdominal wall defects in newborns. First postnatal care consists of defect coverage, avoidance of fluid and heat loss, fluid administration and gastric decompression. Definitive treatment is achieved by defect reduction and abdominal wall closure. Different techniques and timings are used depending on type and size of defect, the abdominal domain and comorbidities of the child. The present review aims to provide an overview of current treatments.

Congenital diaphragmatic hernia and associated omphalocele: a study from the CDHSG registry

BACKGROUND

Congenital Diaphragmatic Hernia (CDH) associated with Omphalocele is a rare condition, and only a few case reports are available in the literature. Both conditions are associated with some degree of pulmonary hypoplasia. We hypothesize that the combination of CDH with Omphalocele might be associated with poorer outcomes.

AIM

The aim of this study was to describe the incidence of this association and postnatal outcomes from the largest database available for CDH.

METHODS

Data from the multicenter, multinational database on infants with CDH (CDHSG Registry) born from 2007 to 2018 was analyzed.

RESULTS

A total of 5730 entries were made into the registry during the study period. The incidence of Omphalocele associated with CDH was 0.63% (36 out of 5730). When comparing posterolateral Bochdalek hernias with Omphalocele (CDH + O) to CDH without Omphalocele (CDH-), CDH + O were born at significantly younger gestational ages. They were sicker directly after birth with significantly lower APGARs at all time points, but received ECMO significantly less often. The distribution of left vs right side or the defect size did not differ but CDH + O required patch in a significantly larger extent. CDH + O had surgical repair significantly later and had significantly higher rates of non-repairs and significantly lower survival rates. The morbidity was significantly higher with longer hospital stays and higher requirements for O2 at 30 DOL.

DISCUSSION

CDH associated with Omphalocele is a rare but more severe condition with higher mortality and morbidity rates. Newborns with these combined conditions can be difficult to stabilize or might pose complicated management problems due to pulmonary hypertension and/or pulmonary hypoplasia.

TYPE OF STUDY

Prognosis Study.

LEVEL OF EVIDENCE

Level I.

Familial occurrence of gastroschisis: a population-based overview on recurrence risk, sex-dependent influence, and geographical distribution

PURPOSE

There is uncertainty over whether familial recurrences in gastroschisis might be higher. Moreover, scant information is available regarding its sociodemographic features. We aim to explore the recurrence risk, sex-dependent influence, and geographical distribution of familial gastroschisis.

METHODS

A systematic review of the literature and data extraction from population-based studies published 1970-2017 (PubMed/MEDLINE) was independently performed by two reviewers. Familial ocurrence of gastroschisis, whereas sociodemographic features from 11 studies were pooled including 862 probands as a base. A descriptive analysis and Chi-square test were performed.

RESULTS

Twenty-four probands had a positive family history of gastroschisis including 49 affected family members, for a recurrence risk of 5.7 and 3% adjusted for proband. Siblings' recurrence was 4.3%. Sex-dependent influence analysis (n = 879, from three studies) evidenced an increased susceptibility to gastroschisis in males (2.5%) compared to females (1.3%) adjusted for proband. Heterogeneity was identified by Fisher's exact test (P = 0.023).

CONCLUSION

Our findings support a greater liability attributable to familial factors on gastroschisis along with significant information for family and prenatal counseling. We suggest that future studies should include for a more accurate account for both familial and environmental confounding factors to uncover relatives and environmental exposures that more limited family histories may have missed.

Complications in neonatal surgery

Neonatal surgery is recognized as an independent discipline in general surgery, requiring the expertise of pediatric surgeons to optimize outcomes in infants with surgical conditions. Survival following neonatal surgery has improved dramatically in the past 60 years. Improvements in pediatric surgical outcomes are in part attributable to improved understanding of neonatal physiology, specialized pediatric anesthesia, neonatal critical care including sophisticated cardiopulmonary support, utilization of parenteral nutrition and adjustments in fluid management, refinement of surgical technique, and advances in surgical technology including minimally invasive options. Nevertheless, short and long-term complications following neonatal surgery continue to have profound and sometimes lasting effects on individual patients, families, and society.

Abdominal wall defects: prenatal diagnosis, newborn management, and long-term outcomes

Omphalocele and gastroschisis represent the most frequent congenital abdominal wall defects a pediatric surgeon is called to treat. There has been an increased reported incidence in the past 10 years mainly due to the diffuse use of prenatal ultrasound. The early detection of these malformations, and related associated anomalies, allows a multidisciplinary counseling and planning of delivery in a center equipped with high-risk pregnancy assistance, pediatric surgery, and neonatology. At present times, closure of defects, even in multiple stages, is always possible as well as management of most of cardiac-, urinary-, and gastrointestinal-associated malformations. The progress, herein discussed, in the care of newborns with abdominal wall defects assures most of them survive and reach adulthood. Some aspects of transition of medical care will also be considered, including fertility and cosmesis.

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.

Clinical risk factors for gastroschisis and omphalocele in humans: a review of the literature

Gastroschisis and omphalocele are usually considered together since they are both congenital abdominal wall defects, and yet their anatomy, embryogenesis, and clinical presentation and problems are quite different. In addition, it appears that the risk factors for their occurrence differ. Etiologic factors contributing to the development of these defects are unknown. To investigate this we have reviewed reports of risk factors for each anomaly and report them here. We conducted a literature search using PubMed (http://www.ncbi.nlm.nih.gov/pubmed/) for risk factors implicated in the development of gastroschisis and omphalocele. The data reviewed here from clinical studies in the literature, closely parallels the data in animal studies which we reported earlier. There is little evidence for a genetic cause in the development of gastroschisis and much evidence supporting the possibility that environmental teratogens are important contributors to the development of this defect. On the other hand, in the case of omphalocele, there was little evidence for environmental factors and substantial data indicating that genetic or familial factors may play an important role.

Familial recurrence of gastroschisis: literature review and data from the population-based birth registry "Mainz Model"

BACKGROUND

Familial forms of gastroschisis are considered rare. A search for these forms in a population-based birth registry in 1993 found a recurrence risk of 3.5% among first-degree relatives. Since then, similar investigations in population-based registries have led to contradictory results.

METHODS

A search of the population-based birth registry "Mainz Model" for familial cases of gastroschisis and a systematic review of the literature were performed.

RESULTS

The Mainz Model database yielded 1 familial recurrence out of 27 gastroschisis cases. From the literature, 37 affected families could be retrieved. Among 412 gastroschises from population-based registries, 10 familial recurrences have been found. These translate into a recurrence risk of 2.4%, with a strong tendency toward underestimation.

CONCLUSION

The existing data support the hypothesis that familial recurrence of gastroschisis is much more likely than previously thought.

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.

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.

Early high C-reactive protein in infants with open abdominal wall defects does not predict sepsis or adverse outcome

AIM

To study CRP values and relate it to outcome in infants with antenatal diagnosis of gastroschisis, exomphalos and other surgical conditions.

METHODS

Over five years, infants admitted to our neonatal unit with gastroschisis, exomphalos and other surgical diagnoses were identified. Serum CRP measurements in first 5 days were studied. Group one included 33 gastroschisis patients, group two, 18 exomphalos patients, and group three, 38 patients with other surgical diagnoses. Outcome measures included TPN days, time to full feeds and duration of hospitalization.

RESULTS

Infants with gastroschisis were more premature (36.9 vs 38.1 weeks) with lower birth weights (2515 vs 3078 g), than infants with exomphalos. CRP values on admission in gastroschisis group were significantly higher than exomphalos and other diagnoses groups (33.7 +/- 6.4 vs 8.8 +/- 6.0 vs 5.7 +/- 2.0, respectively, p < 0.05). All blood cultures were sterile. There was no relationship between high CRP and death or adverse outcome (TPN days, time to full feeds or duration of hospitalization) in the gastroschisis group.

CONCLUSION

Infants with gastroschisis exhibit high early CRP, which may not indicate sepsis or adverse outcome. This increase can complicate the assessment of these infants. Clinicians should be aware of this finding as it could inform management decisions in this group.

Demographic and environmental risk factors for gastroschisis and omphalocele in the National Birth Defects Prevention Study

BACKGROUND

Primary prevention efforts for both gastroschisis and omphalocele are limited by the lack of known risk factors. Our objective was to investigate associations between potential maternal risk factors and gastroschisis and omphalocele within a large population-based sample of participants enrolled in the National Birth Defects Prevention Study (NBDPS).

METHODS

Demographic, health-related, and environmental exposure data from the NBDPS were collected from women with expected delivery dates between October 1997 and December 2003. Data were collected on 485 cases of gastroschisis, 168 cases of omphalocele, and 4967 controls.

RESULTS

Women who had offspring with gastroschisis were younger (adjusted odds ratio [AOR], 0.84; 95% confidence interval [CI], 0.81-0.86) and less likely to be black (AOR, 0.54; 95% CI, 0.34-0.85) than controls. They also were more likely to have smoked (AOR, 1.51; 95% CI, 1.12-2.03), taken ibuprofen (AOR, 1.61; 95% CI, 1.23-2.10), and consumed alcohol (AOR, 1.38; 95% CI, 1.06-1.79) than controls. Women who had offspring with omphaloceles were more likely to have consumed alcohol (AOR, 1.53; 95% CI, 1.04-2.25) and be heavy smokers (AOR, 4.26; 95% CI, 1.58-11.52) than controls.

CONCLUSIONS

Our results suggest a moderately increased risk of gastroschisis among women who used tobacco, alcohol, and ibuprofen during early pregnancy. A modestly elevated risk was observed for omphaloceles among women who used alcohol during the first trimester and among women who were heavy smokers.

Parental age as a risk factor for isolated congenital malformations in a Polish population

Currently available data on the relationship between the prevalence of isolated congenital malformations and parental age are inconsistent and frequently divergent. We utilised the data from the Polish Registry of Congenital Malformations (PRCM) to accurately assess the interplay between maternal and paternal age in the risk of isolated non-syndromic congenital malformations. Out of 902 452 livebirths we studied 8683 children aged 0-2 years registered in the PRCM. Logistic regression was used to simultaneously adjust the risk estimates for maternal and paternal age. Our data indicated that paternal and maternal age were independently associated with several congenital malformations. Based on our data, young maternal and paternal ages were independently associated with gastroschisis. In addition, young maternal age, but not young paternal age, carried a higher risk of neural tube defects. Advanced maternal and paternal ages were both independently associated with congenital heart defects. Moreover, there was a positive association between advanced paternal age and hypospadias, cleft palate, and cleft lip (with or without cleft palate). No significant relationships between parental age and the following congenital malformations were detected: microcephaly, hydrocephaly, oesophageal atresia, atresia or stenosis of small and/or large intestine, ano-rectal atresia or stenosis, renal agenesis or hypoplasia, cystic kidney disease, congenital hydronephrosis, diaphragmatic hernia and omphalocele.

The joint effects of maternal prepregnancy body mass index and age on the risk of gastroschisis

Young maternal age has been associated with an increased risk of gastroschisis, while high maternal weight status has been associated with a decreased risk. We were interested in investigating the joint effect of these two risk factors to identify thresholds in risk associated with body mass index (BMI) for a given age. Data from the National Birth Defects Prevention Study included 464 case infants with gastroschisis and 4842 healthy controls. A generalised additive model with a bivariate spline for continuous maternal age and prepregnancy BMI was used to model the probability of gastroschisis. The bivariate spline in BMI and maternal age was significantly associated with gastroschisis (P = 0.0001) after adjustment for study centre, maternal race/ethnicity, education, income and number of persons supported by income, smoking, alcohol use, vitamin use, vasoconstrictor medication use and gestational diabetes. The data indicate that women who are younger and who have lower BMI are at the greatest risk; a woman with a BMI of 17 who gives birth at age 15 has 7 times the odds (adjusted odds ratio = 7.0 [95% CI 4.2, 11.5]) of having an offspring with gastroschisis compared with a woman of age 24 with a BMI of 23. Furthermore, there was an interaction between maternal age and BMI for this risk. The increased risk of low maternal age and prepregnancy BMI associated with gastroschisis appears to suggest an aetiological role related to biological immaturity for this particular birth defect.

Structural birth defects associated with omphalocele and gastroschisis, Hawaii, 1986-2001

There is limited information on the specific structural birth defects associated with the abdominal wall defects (AWD) omphalocele and gastroschisis, particularly which defects occur with the AWD at greater than expected rates (rates among all infants and fetuses with birth defects other than the AWD). Using data from a population-based birth defects registry in Hawaii, this study calculated the rates for 48 specific structural birth defects among the AWD and compared these rates to the expected rates. There were 60 cases of omphalocele, 96 cases of gastroschisis, and 12,161 infants and fetuses with structural birth defects excluding the AWD among deliveries during 1986-2001. For omphalocele, higher than expected rates were found for 23 (47.9%) of the defects. These involved defects of a variety of organ systems. For gastroschisis, higher than expected rates were found for 8 (16.7%) of the defects, mainly neural tube defects (NTD) and specific defects of the orofacial and gastrointestinal system and the genital and urinary system. Both omphalocele and gastroschisis had elevated rates for NTD, intestinal atresia/stenosis, malrotation of intestines, obstructive genitourinary defects and limb reduction deformities. Certain specific structural birth defects occurred more often than expected with the AWD. The associated birth defects tended to vary between omphalocele and gastroschisis, although there were a few similarities. Due to the small number of cases, further research involving larger amounts of data are warranted.

Increasing prevalence of gastroschisis repairs in the United States: 1996-2003

PURPOSE

Local and state registries have shown recent increases in the prevalence of gastroschisis in the United States and abroad. The purpose of this study was to use a nationally representative database to identify national trends in the prevalence of gastroschisis repairs.

METHODS

Records of infants undergoing gastroschisis repair were identified in the Nationwide Inpatient Sample from 1996 to 2003. Birth data were obtained from the National Center for Health Statistics and used to calculate the rate of procedures/live births stratified by US census region. Survey statistics were used to account for the sampling design of the Nationwide Inpatient Sample database.

RESULTS

Between 1996 and 2003, a total of 9459 gastroschisis repairs were performed in the United States (3 procedures for every 10,000 births). A significant increase in the population-based rate of these procedures was observed in each census regions and nationwide. A twofold higher procedure rate was observed in 2003 than in 1996 (rate ratio, 2.0; 95% confidence interval, 1.1-2.9; P < .001). No significant change in unadjusted hospital mortality was observed regionally or nationally.

CONCLUSIONS

The population-based rate of gastroschisis repairs significantly increased regionally and nationwide between 1996 and 2003, paralleling recent trends described at the local and state level.

Chromosomal Abnormalities Associated With Omphalocele

Fetuses with omphalocele have an increased risk for chromosomal abnormalities. The risk varies with maternal age, gestational age at diagnosis, association with umbilical cord cysts, complexity of associated anomalies, and the contents of omphalocele. There is considerable evidence that genetics contributes to the etiology of omphalocele. This article provides an overview of chromosomal abnormalities associated with omphalocele and a comprehensive review of associated full aneuploidy such as trisomy 18, trisomy 13, triploidy, trisomy 21, 45,X, 47,XXY, and 47,XXX, partial aneuploidy such as dup (3q), dup (11p), inv (11), dup (1q), del (1q), dup (4q), dup (5p), dup (6q), del (9p), dup (15q), dup(17q), Pallister-Killian syndrome with mosaic tetrasomy 12p and Miller-Dieker lissencephaly syndrome with deletion of 17p13.3, and uniparental disomy (UPD) such as UPD 11 and UPD 14. Omphalocele is a prominent marker for chromosomal abnormalities. Perinatal identification of omphalocele should alert chromosomal abnormalities and familial unbalanced translocations, and prompt thorough cytogenetic investigations and genetic counseling.

Gastroschisis and associated defects: An international study

Our objective was to evaluate the frequency and type of malformations associated with gastroschisis in a large pool of international data, to identify malformation patterns, and to evaluate the role of maternal age in non-isolated cases. Case-by-case information from 24 registries, all members of the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR), were evaluated. After the exclusion of other abdominal wall defects cases were classified as: (a) isolated; (b) recognizable syndrome, chromosomal or not; (c) multiple congenital anomalies (MCA). Our results showed that out of 3,322 total cases 469 non-isolated cases were registered (14.1%): 41 chromosomal syndromes, 24 other syndromes, and 404 MCA. Among MCA four groups of anomalies were most frequent: CNS (4.5%), cardio-vascular (2.5%), limb (2.2%), and kidney anomalies (1.9%). No similar patterns emerged except two patterns resembling limb-body wall complex and OEIS. In both of them the gastroschisis could be however misclassified. Chromosomal trisomies and possibly non-syndromic MCA are associated with an older maternal age more than isolated cases. On consideration of our data and the most valid studies published in the literature, the best estimate of the proportion of gastroschisis associated with major unrelated defects is about 10%, with a few cases associated to recognizable syndromes. Recognized syndromes with gastroschisis seem to be so exceptional that the well documented and validated cases are worth being published as interesting case report. An appropriate case definition in etiological studies should include only isolated gastroschisis after an appropriate definition of isolated and non-isolated cases and a thorough case-by-case review.

Comparison of trends in gastroschisis and prenatal illicit drug use rates

Gastroschisis rates have been increasing over time, and gastroschisis risk is elevated in women of young maternal age. Similar patterns were reported for prenatal illicit drug use in Hawaii. Cases of gastroschisis and prenatal use of methamphetamine, cocaine, or marijuana among deliveries in Hawaii during 1986-2002 were identified from a common registry. The pattern of gastroschisis rates by maternal age and time period was compared to the pattern of prenatal illicit drug use rates. The prenatal marijuana use rate among gastroschisis cases was significantly greater than among the total population. Prenatal methamphetamine and cocaine rates were not significantly elevated among gastroschisis cases. The gastroschisis rate was highest among the youngest maternal age group, then declined with increasing maternal age. Only prenatal marijuana use demonstrated a similar pattern, but the ratio of the gastroschisis rate to the prenatal marijuana use rate declined with increasing maternal age. The gastroschisis rate increased during the 17-yr period. Both methamphetamine and marijuana demonstrated similar annual trends; however, the ratio of the gastroschisis rates to the illicit drug use rates varied greatly for the 2 drugs over time. The results of this investigation suggest that prenatal illicit drug use of methamphetamine, cocaine, and marijuana may not play a major role in explaining the increased risk of gastroschisis among younger mothers and the annual increases that have been reported.

Fat intake and the risk of gastroschisis

BACKGROUND

Young age has been associated with an increased risk of gastroschisis. It has been suggested that the pathogenesis of gastroschisis may be related to vascular disruption. Nutrients that may be associated with vasoconstriction include dietary fat and its subtypes. The objective of this study was to examine the association between dietary fats and gastroschisis and whether maternal age modified this association.

METHODS

Data came from the National Birth Defects Prevention Study (NBDPS), which included 304 isolated gastroschisis cases and 3313 controls. Dietary intake in the year prior to conception was ascertained using a food frequency questionnaire, and included total, saturated, monosaturated, and polyunsaturated fat and cholesterol. Unconditional logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for confounders. Age and smoking were tested as effect modifiers.

RESULTS

Higher mean intakes of total energy, total fat, and cholesterol as well as the subtypes of fats were found for gastroschisis cases compared to controls. Cases were more likely to be in the middle (adjusted OR [AOR], 1.3; 95% CI, 0.9-1.9) and highest (AOR, 1.2; 95% CI, 0.8-1.7) tertile of total fat intake compared to controls. This pattern was also true for saturated fat intake. No association was found for mono or polyunsaturated fat. Cases were less likely to be in the middle (AOR, 0.6; 95% CI, 0.4-0.9) and highest (AOR, 0.8; 95% CI, 0.6-1.2) tertiles for cholesterol. There was no evidence of effect modification.

CONCLUSIONS

A possible weak effect of increased risk of gastroschisis associated with higher intakes of total fat or saturated fat was found in the NBDPS; however, this did not help to explain why younger aged women are at greater risk of having an infant with this type of birth defect.

Epidemiology of gastroschisis in metropolitan Atlanta, 1968 through 2000

BACKGROUND

An increase in the rate of gastroschisis has been documented by birth defects surveillance systems in the United States and in other countries. This study sought to evaluate historical trends in the rate of gastroschisis in Atlanta, Georgia, and to describe the epidemiology of gastroschisis over 33 years.

METHODS

Gastroschisis cases were identified through the Metropolitan Atlanta Congenital Defects Program (MACDP) from 1968 through 2000. Poisson regression techniques were used to evaluate trends over time. Data on covariates were compared for three maternal age groups (< or =19, 20-24, and > or =25 years).

RESULTS

From 1968 through 1975, the rate of gastroschisis was stable at 0.8 per 10,000 births. After 1975, the rate of gastroschisis was 2.3 per 10,000 births with no significant increase observed from 1976 through 2000. The rate of gastroschisis was six times higher among teenage mothers compared with mothers > or =25 years of age. Affected infants born to teenage mothers were less likely to be born to Black mothers compared to White mothers (rate ratio [RR], 0.4; 95% confidence interval [CI], 0.2-0.6). This was also true for mothers 20-24 years of age (RR, 0.5; 95% CI, 0.3-0.8) but not for mothers 25 years of age or older (RR, 1.6; 95% CI, 0.9-2.7).

CONCLUSIONS

An increase in the rate of gastroschisis was observed in the mid-1970s, but no temporal trend has been observed since that time. In light of recent reports of an increasing prevalence of gastroschisis in the United States, continued monitoring of this birth defect is warranted.

Omphalocele: clinical outcomes in cases with normal karyotypes

OBJECTIVE

This study was undertaken to examine neonatal outcomes in karyotypically normal cases of omphalocele with respect to mode of delivery, presence of associated anomalies, presence of extracorporeal liver, and method of abdominal wall closure.

STUDY DESIGN

We reviewed 36 cases of omphalocele with delivery at University of North Carolina Hospitals between 1988 and 2001. Elective terminations and pregnancies resulting in miscarriage before 20 weeks' gestation were excluded.

RESULTS

Perinatal mortality rate was 19%. Rate of composite neonatal morbidity was 25%. Associated major anomalies were present in 11 (31%) cases and were associated with increased neonatal mortality. Cesarean deliveries were performed in 21 (58%) cases and were not associated with increased primary closure rates or decreased neonatal morbidity and mortality. Extracorporeal liver was present in 27 (75%) cases and was associated with decreased rates of primary closure but did not affect neonatal outcome.

CONCLUSION

In cases of ongoing omphalocele, perinatal mortality rates are low in the absence of associated anomalies or genetic defects. Intracorporeal liver was not associated with increased rates of associated anomalies or was it associated with increased neonatal morbidity or mortality.

Aspirin consumption during the first trimester of pregnancy and congenital anomalies: a meta-analysis

OBJECTIVE

The purpose of this study was to determine, on the basis of published reports, whether aspirin use during the first trimester of pregnancy is associated with an increased risk of congenital malformations.

STUDY DESIGN

We reviewed the literature for published studies that reported exposure to aspirin during the first trimester of pregnancy and congenital malformations. Two reviewers independently determined whether a study should be included in the final analysis and extracted the data. We calculated the pooled odds ratio and 95% CI.

RESULTS

Twenty-two studies met the inclusion criteria. In the eight studies that reported an overall risk, the risk of congenital malformations in offspring of women who were exposed to aspirin was not significantly higher than that in control subjects (odds ratio, 1.33; 95% CI, 0.94-1.89). However, a significantly increased risk of gastroschisis (odds ratio, 2.37; 95% CI, 1.44-3.88) was found.

CONCLUSION

We found no evidence of an overall increase in the risk of congenital malformations that could be associated with aspirin. Aspirin exposure during the first trimester may be associated with an increased risk of gastroschisis.

Occurrence of omphalocele in relation to maternal multivitamin use: a population-based study

OBJECTIVE

We evaluated the association between mothers' use of multivitamin supplements and their infants' risk for omphalocele, a congenital anomaly of the abdominal wall. Omphalocele can occur in certain multiple congenital anomaly patterns with neural tube defects, for which a protective effect of multivitamins with folic acid has been demonstrated.

METHODS

We used data from a population-based case-control study of infants born from 1968-1980 to mothers residing in metropolitan Atlanta. Case-infants with nonsyndromic omphalocele (n = 72) were actively ascertained from multiple sources. Control-infants (n = 3029), without birth defects, were selected from birth certificates by stratified random sampling.

RESULTS

Compared with no use in the periconceptional period, periconceptional use of multivitamin supplements (regular use from 3 months before pregnancy through the first trimester of pregnancy) was associated with an odds ratio for nonsyndromic omphalocele of 0.4 (95% confidence interval [CI]: 0.2-1.0). For the subset comprising omphalocele alone or with selected midline defects (neural tube defects, hypospadias, and bladder/cloacal exstrophy), the odds ratio was 0.3 (95% CI: 0.1-0.9). These estimates were similar when the reference group also included women who began using multivitamins late in pregnancy (during the second or third month of pregnancy). The small number of participants limited the precision of subgroup analyses and translated into wide confidence intervals that included unity.

CONCLUSIONS

Periconceptional multivitamin use was associated with a 60% reduction in the risk for nonsyndromic omphalocele. These findings await replication from additional studies to confirm the findings, generate more precise estimates, and detail possible mechanisms of actions.

Abdominal wall defects in Denmark, 1970-89

In the last two to three decades, increasing rates of gastroschisis but not of omphalocele have been reported from different parts of the world. The present study represents a register containing 469 children born with abdominal wall defects based on data retrieved from 20 birth cohorts (1970-89) in three nationwide registries. A tentative estimate of the completeness as regards identification of liveborn and stillborn infants is a minimum of 95% and 90% respectively. All cases were reclassified to 166 cases of gastroschisis, 258 of omphalocele and 16 of gross abdominal wall defect. The average point prevalence at birth of gastroschisis was 1.33 per 10 000 live and stillbirths. During the first decade, an increase in prevalence occurred culminating in 1976, followed by a decrease reaching its initial value in 1983 and then a new increase. Overall, no significant linear trend could be demonstrated for the entire period. The average point prevalence at birth for omphalocele was 2.07 and for gross abdominal wall defect 0.12 per 10 000 live and stillbirths with no significant change in the period. The geographical distribution of gastroschisis and omphalocele showed no difference per county.

Evaluation of prenatal ultrasound diagnosis of fetal abdominal wall defects by 19 European registries

OBJECTIVES

To evaluate the current effectiveness of routine prenatal ultrasound screening in detecting gastroschisis and omphalocele in Europe.

DESIGN

Data were collected by 19 congenital malformation registries from 11 European countries. The registries used the same epidemiological methodology and registration system. The study period was 30 months (July 1st 1996-December 31st 1998) and the total number of monitored pregnancies was 690,123.

RESULTS

The sensitivity of antenatal ultrasound examination in detecting omphalocele was 75% (103/137). The mean gestational age at the first detection of an anomaly was 18 +/- 6.0 gestational weeks. The overall prenatal detection rate for gastroschisis was 83% (88/106) and the mean gestational age at diagnosis was 20 +/- 7.0 gestational weeks. Detection rates varied between registries from 25 to 100% for omphalocele and from 18 to 100% for gastroschisis. Of the 137 cases of omphalocele less than half of the cases were live births (n = 56; 41%). A high number of cases resulted in fetal deaths (n = 30; 22%) and termination of pregnancy (n = 51; 37%). Of the 106 cases of gastroschisis there were 62 (59%) live births, 13 (12%) ended with intrauterine fetal death and 31 (29%) had the pregnancies terminated.

CONCLUSIONS

There is significant regional variation in detection rates in Europe reflecting different policies, equipment and the operators' experience. A high proportion of abdominal wall defects is associated with concurrent malformations, syndromes or chromosomal abnormalities, stressing the need for the introduction of repeated detailed ultrasound examination as a standard procedure. There is still a relatively high rate of elective termination of pregnancies for both defects, even in isolated cases which generally have a good prognosis after surgical repair.

Risk factors in congenital abdominal wall defects (omphalocele and gastroschisi): a study in a series of 265,858 consecutive births

The aim of this study was to describe the prevalence at birth of two abdominal wall defects (AWD), omphalocela and gastroschisis and to identify possible etiologic factors. The AWD came from 265,858 consecutive births of known ouome registered in the registry of congenital malformations of Strasbourg for the period 1979 to 1998. Request information on the child, the pregnancy, the parents and the family was obtained for cases and for controls. Hundred five cases with AWD were analysed, 55.2 % were omphalocele and 44.8 % were gastroschisis. The mean prevalence rate for omphalocele was 2.18 per 10,000 and for gastroschisis 1.76 per 10,000. Associated malformations were found in 74.1 % of omphalocele compared with 53.2 % of gastroschisis; 29.3 % of fetuses with omphalocele had an abnormal karyotype, 44,8 % had a recognizable syndrome, association or an unspecified malformation pattern; 51.0 % of fetuses with gastroschisis had additional malformations that were not of chromosomal origin, but 1 case. Antenatal ultrasound examination was able to detect 39 (67.2 %) cases of omphaloceles and 27 (57.4 %) cases of gastroschisis. In 30 (51.7 %) cases of omphalocele and in 7 (14.9 %) cases of gastroschisis parents opted for termination of pregnancy. The overall survival rate was 14 (24.1 %) for omphalocele and 30 (63.8 %) for gastroschisis. Weight, length and head circumference at birth of infants with AWD were less than those of controls. The weight of placenta of infants with AWD was not different from the weight of placenta of controls. Gastroschisis was associated with significantly younger maternal age than omphalocele. Pregnancies with AWD were more often complicated by threatened abortion, oligohydramnios and polyhydramnios. Mothers of children with AWD took more often medication during pregnancy than mothers of controls.

Limb-body wall complex: 4 new cases illustrating the importance of examining placenta and umbilical cord

Limb-body wall complex (LBWC) is a rare, sporadic, congenital defect defined as a combination of at least two of three characteristics: 1. limb defects, 2. anterior body wall defects, and 3. exencephaly or encephalocoele with/without facial clefts. Three pathogenic mechanisms have been proposed: early amnion rupture, vascular disruption and embryonic dysgenesis. In this study we carried out the pathological evaluation of four fetuses with LBWC and their placentas. None of the cases had craniofacial defects. Three fetuses showed an abdominal wall defect with eventration of abdominal organs, cloacal exstrophy, absent external genitalia, abnormal internal genitalia, scoliosis and lower limb defects. One fetus showed failure of closure of both thoracic and abdominal walls with ectopia cordis, evisceration of left lung and abdominal organs, severe reduction defect of left arm, but normal colon, anus, bladder, genitalia and lower limbs. All cases had a short, malformed umbilical cord, incompletely covered by amnion. The umbilical vessels were embedded in an amniotic sheet which connected the skin margin of the anterior body wall defect to the placenta. These anomalies suggest an abnormal body stalk development as a pathogenic mechanism for LBWC. Prenatally, the abnormal fetoplacental attachment can be detected ultrasonographically by the end of the first gestational trimester. Postnatally, the examination of placenta, umbilical cord and membranes is crucial in confirming the diagnosis of LBWC.

Congenital anterior abdominal wall defects in the north of England, 1986-1996: occurrence and outcome

The aim was to describe trends in prevalence, maternal age-specific prevalence, associated anomalies, clinical outcomes and the sensitivity of antenatal diagnosis of congenital anterior abdominal wall defects (in particular gastroschisis and exomphalos). Data were identified from a population-based register of major congenital abnormalities in the Northern health region of England, the Northern Congenital Abnormality Survey (NorCAS), between 1986 and 1996. 296 cases were notified; there were 133 cases of gastroschisis, 98 exomphalos, 30 limb-body wall defects and 23 other anterior abdominal wall defects. 12 cases could not be classified. In 19 (6 per cent) the initial diagnosis was changed following case review. 30 (30.6 per cent) cases of exomphalos were associated with a chromosomal anomaly compared with 1 (0.8 per cent) case of gastroschisis. The total prevalence for the 11 years was 6.33 (95 per cent CI=5.57-7.08) per 10 000 live births, still births and terminations of pregnancy, and the overall birth prevalence was 4.30 (95 per cent CI=3.68-4.93) per 10 000 live births and still births. For gastroschisis, there was a significant increase over the study period in both the total prevalence (1.48 in 1986 to 5.29 per 10 000 in 1996; chi(2)=8.41, p=0.00433) and the birth prevalence (1.48 in 1986 to 4.72 per 10 000 in 1996; chi(2)=7.42, p=0.00644), but there was no such significant increase for exomphalos (total prevalence chi(2)=2.29, p=0.13055; birth prevalence chi(2)=0.16, p=0.69348). The maternal age-specific prevalence was highest in the 11-19 year age group for gastroschisis but in the 35-39 year age group for exomphalos. Fewer pregnancies with gastroschisis resulted in a termination and a greater proportion of cases were alive at one year compared with exomphalos. The sensitivity of abnormality detection by ultrasonography was 75 per cent and 77.3 per cent for gastroschisis and exomphalos, respectively. Antenatal diagnosis improved from 47.4 per cent during 1986-91 to 80 per cent between 1992-96 for gastroschisis (chi(2)=5.7, p=0.00169), and from 55.6 per cent to 68.8 per cent for isolated exomphalos, although this increase was not significant. Total and birth prevalence of gastroschisis increased in the Northern region between 1986 and 1996. For exomphalos, there was a trend towards an increase in total prevalence and towards a decrease in birth prevalence. This decreasing trend has been accompanied by improvements in antenatal detection and subsequent termination of cases of exomphalos associated with other anomalies.

Association between mothers' nutrient intake and their offspring's risk of gastroschisis

The young age of mothers of infants with gastroschisis, a congenital defect of the abdominal wall, suggested that deficient nutrition, with maternal-fetal competition for nutrients, could be a risk factor for gastroschisis. This population-based hypothesis-generating study consisted of 55 cases of gastroschisis and 182 matched controls. We assessed maternal nutrient intake during the trimester before conception with a self-reported food-frequency questionnaire and screened 38 nutrients to identify those most likely to be associated with gastroschisis. We used statistical classification trees to empirically generate cutpoints that determined the low and high levels of nutrient intakes corresponding to the risk of gastroschisis; cutpoints for most nutrients were similar to the corresponding recommended daily dietary allowances (RDAs). In univariate analysis, low intake of several nutrients emerged as the leading risk factors: carotenoids, e.g., alpha-carotene (odds ratio (OR) = 4.6; 95% confidence interval (CI) = 2.2-9.5), beta-carotene (OR = 3.1; 95% CI = 1.6-6.0); amino-acid compounds, e.g., total glutathione (OR = 3.5; 95% CI = 1.7-7.2); vitamin C (OR = 2.2; 95% CI = 1.5-7.8); vitamin E (OR = 2.3; 95% CI = 1.2-4.4); and minerals, fiber, and the fruit-and-vegetable group (OR = 3.1; 95% CI = 1.5-6.2). High intake of nitrosamines (OR = 2.4; 95% CI = 1.3-4.5) was also a good candidate. Many nutrient values were correlated and, in multivariate analysis, those most associated with gastroschisis were low alpha-carotene (OR = 4.3; 95% CI = 1.9-9.8), low total glutathione (OR = 3.3; 95% CI = 1.4-7.6), and high nitrosamines (OR = 2.6; 95% CI = 1.3-5.4). Adjusting for variables associated with gastroschisis in previous analyses of this population did not substantially alter those risks. These results suggest that maternal dietary inadequacy may be a risk factor for gastroschisis, and the three nutrients that emerged from the nutrient screening appear to be the best candidates to examine in further epidemiological analyses or biological studies.

Congenital anterior abdominal wall defects in England and Wales 1987-93: retrospective analysis of OPCS data

OBJECTIVES

Analysis of incidence and characteristics of congenital abdominal wall defects, with special reference to the differences between the incidence of gastroschisis and exomphalos (omphalocele).

DESIGN

Retrospective analysis using data from the Office of Population Censuses and Surveys (recoded to differentiate exomphalos and gastroschisis) and the National Congenital Malformation Notification Scheme.

SETTING

England and Wales, 1987 to 1993.

RESULTS

1043 congenital anterior abdominal wall defects were notified within the seven year study period. Of these, 539 were classified as gastroschisis, 448 as exomphalos, 19 as "prune belly syndrome," and 37 as "unclassified." Gastroschisis doubled in incidence from 0.65 in 1987 to 1.35 per 10,000 total births in 1991, with little further change; the incidence of exomphalos decreased from 1.13 to 0.77 per 10000 births. The overall incidence of notified congenital abdominal wall defects was 2.15 per 10000 total births. Gastroschisis was associated with a lower overall maternal age than exomphalos and with a significantly lower proportion of additional reported congenital malformations (5.0%) than in the cohort with exomphalos (27.4%) (odds ratio 0.14, 95% confidence interval 0.09 to 0.22; P < 0.001). The sex ratio of the two cohorts was the same. The incidence of gastroschisis and exomphalos was higher in the northern regions of England than in the south east of the country.

CONCLUSIONS

The national congenital malformation notification system showed an increasing trend in the incidence of fetuses born with gastroschisis and a progressive decreasing incidence of exomphalos in England and Wales between 1987 and 1993. Although the reasons for this are likely to be multifactorial, a true differential change seems likely. The observed increase in incidence of gastroschisis relative to exomphalos and the differentiation in maternal age have implications for resource management within the NHS and warrant further epidemiological monitoring. Regional differences may be due to a dietary or environmental factor, which requires further study.

Maternal medications and environmental exposures as risk factors for gastroschisis

In a case-control study of gastroschisis, we evaluated the risks associated with mother's first-trimester use of medications and with hobby or occupational exposures for 110 cases and 220 controls without a birth defect. Mothers of cases and controls were age-matched. For hobby or occupational exposures, we found significantly elevated risks for high levels of solvents (odds ratio (OR) = 3.8; 95% confidence interval (CI) = 1.6-9.2) and for colorants (OR = 2.3; 95% CI = 1.3-4.0). For medications, we found significantly elevated risks for two strong cyclooxygenase inhibitors, aspirin (OR = 4.7; 95% CI = 1.2-18.1) and ibuprofen (OR = 4.0; 95% CI = 1.0-16.0), but not for acetaminophen, a weak cyclooxygenase inhibitor. Periconceptional exposure to X rays was also associated with gastroschisis (OR = 2.5; 95% CI = 1.2-5.5), but exposure to antibiotics, antinauseants, sulfonamides, or oral contraceptives was not. We also found elevated risks for two decongestants, pseudoephedrine (OR = 2.1; 95% CI = 0.8-5.5) and phenylpropanolamine (OR = 10.0; 95% CI = 1.2-85.6). For the group of all decongestants, including also oxymetazoline and ephedrine, the risk was significantly elevated (OR = 2.4; 95% CI = 1.0-5.4). Controlling in multivariate analyses for several demographic and pregnancy variables associated with gastroschisis in a previous analysis [Torfs et al. (1994) Teratology 50: 44-53] did not substantially change the level or direction of the associations. Most of these associations are for vasoactive substances, which supports a vascular hypothesis for the pathogenesis of gastroschisis.

Omphalocele and gastroschisis in Europe: a survey of 3 million births 1980-1990. EUROCAT Working Group

A total of 732 cases of omphalocele and 274 cases of gastroschisis was registered in 21 regional registers in Europe (EUROCAT registers) during the period 1980-1990. The total prevalence rates were 2.52 per 10,000 for omphalocele and 0.94 per 10,000 for gastroschisis. There was significant heterogeneity in total prevalence rates among regions for omphalocele. Consistently higher than average total prevalence rates of omphalocele were found in the five centers of the British Isles. This was in large part linked to the association between omphalocele and neural tube defects. A significant female excess among the cases of omphalocele associated with neural tube defects, in comparison with an insignificant male excess for other cases of omphalocele, was observed. Geographical differences in the total prevalence of gastroschisis are partly explained by differences in maternal age distributions in the populations surveyed. Omphalocele was an isolated malformation in 46% of cases; gastroschisis was isolated in 79% of cases. The average birthweight and gestational age of both isolated and multiply malformed cases of both omphalocele and gastroschisis were low, especially for multiply malformed cases, and to a greater extent for isolated gastroschisis than for isolated omphalocele. Prenatal diagnosis leading to termination of pregnancy was reported in 33.2% of omphalocele and in 26.5% of gastroschisis cases, demonstrating the considerable impact of current prenatal screening programs. On the basis of clinical manifestations, epidemiologic characteristics, and the presence and type of additional malformations, omphalocele and gastroschisis can be considered heterogeneous conditions.

Anophthalmia and benomyl in Italy: a multicenter study based on 940,615 newborns

Following the report on clusters of anophthalmia and microphthalmia in England and Wales and their possible relation to the pesticide Benomyl, we analyzed the situation in Italy for the period 1986 to 1990 using data from the Italian registries of congenital malformations and national data on Benomyl use. Of 940,615 consecutive births, 33 cases of clinical anophthalmia and 78 cases of microphthalmia were reported (birth prevalence: 0.35 and 0.83/10,000). Birth prevalence by region for 18 of Italy's 20 political regions was evaluated for the two malformations, grouped together after exclusion of defects associated with chromosomal anomalies, no dishomogeneity in space or time among registries or among regions was observed for the study period. In no region was a statistically significant difference identified between observed and expected overall birth prevalence. Correlation analysis between the prevalence of micro/anophthalmia and Benomyl use by region showed a negative, nonsignificant coefficient, and an inverse correlation was found when the 18 regions were divided into four groups by increasing levels of Benomyl use. Parental occupation in agriculture did not seem to be associated with micro/anophthalmia when compared to a control group affected with isolated prearicular tags (odds ratio 0.63; CL 0.07-2.52). On the basis of these results, though the limits intrinsic to ecologic correlation studies must be taken into account, an association between Benomyl use and congenital micro/anophthalmia appears to be unlikely.