Monitoring of risk factor/outcome combinations:A valuable supplement to birth defect monitoring

Since the thalidomide disaster in the early sixties many birth defect monitoring systems and registries have been set up to detect changes in the frequencies of specific birth defects. The primary methods of monitoring have been the statistical analysis of data on birth prevalences and teratologic analysis. The yield of this monitoring effect has nevertheless been low when one considers the lack of etiologic factors detected in this way. We therefore propose an additional strategy involving (periodic) classification of all cases in a birth defect registry according to possible risk factors and notified anomalies coupled with a search for specific associations between risk factors and (patterns of) anomalies. We here present data showing the sensitivity of the method. Sensitivity was studied by looking at some already well known associations between risk factors and congenital anomalies in our registry involving 1850 cases. The associations studied were neural tube defects and maternal use of valproic acid, numerical chromosomal anomalies and advanced maternal age, gastroschisis and low maternal age, and autosomal recessive disorders and parental consanguinity. Each of these associations was apparent in the registry, suggesting that risk factor/outcome monitoring as described here is a potentially strong method for finding new etiologic factors in birth defects.</p

The association of prenatal diagnoses with mortality and long-term morbidity in children with specific isolated congenital anomalies: a European register-based cohort study

Objectives: To compare 5-year survival rate and morbidity in children with spina bifida, transposition of great arteries (TGA), congenital diaphragmatic hernia (CDH) or gastroschisis diagnosed prenatally with those diagnosed postnatally. Methods: Population-based registers’ data were linked to hospital and mortality databases. Results: Children whose anomaly was diagnosed prenatally (n = 1088) had a lower mean gestational age than those diagnosed postnatally (n = 1698) ranging from 8 days for CDH to 4 days for TGA. Children with CDH had the highest infant mortality rate with a significant difference (p &lt; 0.001) between those prenatally (359/1,000 births) and postnatally (116/1,000) diagnosed. For all four anomalies, the median length of hospital stay was significantly greater in children with a prenatal diagnosis than those postnatally diagnosed. Children with prenatally diagnosed spina bifida (79% vs 60%; p = 0.002) were more likely to have surgery in the first week of life, with an indication that this also occurred in children with CDH (79% vs 69%; p = 0.06). Conclusions: Our findings do not show improved outcomes for prenatally diagnosed infants. For conditions where prenatal diagnoses were associated with greater mortality and morbidity, the findings might be attributed to increased detection of more severe anomalies. The increased mortality and morbidity in those diagnosed prenatally may be related to the lower mean gestational age (GA) at birth, leading to insufficient surfactant for respiratory effort. This is especially important for these four groups of children as they have to undergo anaesthesia and surgery shortly after birth. Appropriate prenatal counselling about the time and mode of delivery is needed

Creating a population-based cohort of children born with and without congenital anomalies using birth data matched to hospital discharge databases in 11 European regions: Assessment of linkage success and data quality

Linking routinely collected healthcare administrative data is a valuable method for conducting research on morbidity outcomes, but linkage quality and accuracy needs to be assessed for bias as the data were not collected for research. The aim of this study was to describe the rates of linking data on children with and without congenital anomalies to regional or national hospital discharge databases and to evaluate the quality of the matched data. Eleven population-based EUROCAT registries participated in a EUROlinkCAT study linking data on children with a congenital anomaly and children without congenital anomalies (reference children) born between 1995 and 2014 to administrative databases including hospital discharge records. Odds ratios (OR), adjusted by region, were estimated to assess the association of maternal and child characteristics on the likelihood of being matched. Data on 102,654 children with congenital anomalies were extracted from 11 EUROCAT registries and 2,199,379 reference children from birth registers in seven regions. Overall, 97% of children with congenital anomalies and 95% of reference children were successfully matched to administrative databases. Information on maternal age, multiple birth status, sex, gestational age and birthweight were &gt;95% complete in the linked datasets for most regions. Compared with children born at term, those born at ≤27 weeks and 28-31 weeks were less likely to be matched (adjusted OR 0.23, 95% CI 0.21-0.25 and adjusted OR 0.75, 95% CI 0.70-0.81 respectively). For children born 32-36 weeks, those with congenital anomalies were less likely to be matched (adjusted OR 0.78, 95% CI 0.71-0.85) while reference children were more likely to be matched (adjusted OR 1.28, 95% CI 1.24-1.32). Children born to teenage mothers and mothers ≥35 years were less likely to be matched compared with mothers aged 20-34 years (adjusted ORs 0.92, 95% CI 0.88-0.96; and 0.87, 95% CI 0.86-0.89 respectively). The accuracy of linkage and the quality of the matched data suggest that these data are suitable for researching morbidity outcomes in most regions/countries. However, children born preterm and those born to mothers aged &lt;20 and ≥35 years are less likely to be matched. While linkage to administrative databases enables identification of a reference group and long-term outcomes to be investigated, efforts are needed to improve linkages to population groups that are less likely to be linked.</p

Prevalence of congenital heart defects in Europe, 2008-2015: A registry‐based study

Background: The total prevalence of congenital heart defects (CHDs) varies by populations and over time. Studies that examine trends in the prevalence of CHD in different regions may shed light on our understanding of the occurrence of CHD and the impact of different risk factors. Objectives: To examine trends in total and live birth prevalence of nonsyndromic CHD in Europe between the years 2008 and 2015 and to investigate if the decreasing trend reported by previous studies is continuing. Methods: Cases of CHD delivered between January 1, 2008 and December 31, 2015 notified to 25 population-based EUROCAT (European Surveillance of Congenital Anomalies) registries in 14 countries, formed the population-based case-series. Prevalence (total/live) rates and 95% confidence intervals were calculated as the number of cases per 10,000 births (live and stillbirths). Time trends in prevalence of all nonsyndromic CHDs and for three CHD severity groups (very severe, severe, and less severe) were plotted using a Poisson regression multilevel approach. Results: The total prevalence of nonsyndromic CHD was 57.1 per 10,000 births (live births and stillbirths) for the 8-year period and remained stable across the three CHD severity groups while the live birth prevalence was 60.2 per 10,000 births. There was considerable variation in the reported total CHD prevalence and the direction of trends by registry. A decreasing prevalence ofCHD was observed for the Norway and England/Wales registries, whereas the CHD prevalence increased for registries in Italy and Croatia. Conclusions: The total prevalence of CHD in Europe between the years 2008 and 2015 remained stable for all CHD and across the three CHD severity groups. The decreasing trend reported by previous studies has not continued. However, we found significant differences in the total and live birth prevalence by registry.info:eu-repo/semantics/publishedVersio

Maternal age and the prevalence of congenital heart defects in Europe, 1995–2015: A register‐based study

Background: Evidence on the direction and strength of association between maternal age and the prevalence of congenital heart defects (CHD) in different age group categories is conflicting. Some studies have illustrated different trends with an increase in prevalence in younger and older age groups while other studies have reported a linear relationship. Given the increase in maternal age over recent years, it is important to study the CHD prevalence by maternal age. Objectives: To examine the association between maternal age and the prevalence of CHD in Europe between 1995 and 2015 using population-based data from 24 registries belonging to the European Surveillance of Congenital Anomalies (EUROCAT) network. Methods: Associations over time of all nonsyndromic CHD according to maternal age category and for three CHD severity groupings (severity group I: very severe; severity group II: severe; severity group III: less severe) were examined using Bayesian multilevel Poisson regression modeling. Further subgroup analyses were undertaken within four maternal age-bands: ≤24, 25–29, 30–34 and 35–44 years. Descriptive summaries are also presented. Results: There were 51,608 nonsyndromic CHD cases in Europe over the 20-year study period. Total prevalence for all CHD combined was increased for younger mothers (≤24 years) and for mothers 35–44 years of age when compared with mothers aged 25–29 years (reference group) (IRR: 1.05, 95% CI: 1.02, 1.07). The total prevalence was increased for severity group I (very severe) only for younger mothers compared to those aged 25–29 years (IRR: 1.14, 95% CI: 1.04, 1.23). We found an increased prevalence of the following CHD subtypes: double outlet right ventricle (IRR:1.33, 95% CI: 1.09, 1.60), hypoplastic left heart syndrome (IRR: 1.18, 95% CI: 1.05, 1.32), hypoplastic right heart syndrome (IRR: 1.41, 95% CI: 1.05, 1.84), atrioventricular septal defect (IRR: 1.15, 95% CI: 1.01, 1.32), coarctation of aorta (IRR: 1.15, 95% CI: 1.03, 1.28) and atrial septal defect (IRR: 1.08, 95% CI: 1.02, 1.13). For older mothers (35–44 years) compared to the reference category, we observed an increased risk in the prevalence for severity group II (IRR: 1.09, 95% CI: 1.03, 1.14), severity group III (IRR: 1.05, 95% CI: 1.01, 1.08) and an increased prevalence of the CHD subtypes: Pulmonary valve stenosis (IRR: 1.22, 95% CI: 1.09, 1.34), ASD (IRR: 1.07, 95% CI: 1.02, 1.13), CoA (IRR: 1.18, 95% CI: 1.06, 1.32) and Tetralogy of Fallot (IRR: 1.14, 95% CI: 1.01, 1.28). Finally, for all age categories compared to the reference category, different associations of ASD and an increased prevalence of CoA was also observed. Conclusions: Based on data for cases of CHD from 24 European populationbased registries, evidence of a positive association between maternal age and the total prevalence of CHD for younger (≤24 years old) and older (35–44 years old) mothers was observed. The results suggest that young maternal age (≤24 years old) is a factor associated with severe CHD phenotypes while a positive association between advanced maternal age (35–44 years old) and mild CHD phenotypes was observed.info:eu-repo/semantics/publishedVersio

Spectrum of congenital anomalies among VACTERL cases: a EUROCAT population-based study

Background: The VACTERL (Vertebral anomalies, Anal atresia, Cardiac malformations, Tracheo-Esophageal fistula, Renal anomalies, Limb abnormalities) association is the non-random occurrence of at least three of these congenital anomalies: vertebral, anal, cardiac, tracheo-esophageal, renal, and limb anomalies. Diagnosing VACTERL patients is difficult, as many disorders have multiple features in common with VACTERL. The aims of this study were to clearly outline component features, describe the phenotypic spectrum among the largest group of VACTERL patients thus far reported, and to identify phenotypically similar subtypes. Methods: A case-only study was performed assessing data on 501 cases recorded with VACTERL in the JRC-EUROCAT (Joint Research Centre-European Surveillance of Congenital Anomalies) central database (birth years: 1980–2015). We differentiated between major and minor VACTERL features and anomalies outside the VACTERL spectrum to create a clear definition of VACTERL. Results: In total, 397 cases (79%) fulfilled our VACTERL diagnostic criteria. The most commonly observed major VACTERL features were anorectal malformations and esophageal atresia/tracheo-esophageal fistula (both occurring in 62% of VACTERL cases), followed by cardiac (57%), renal (51%), vertebral (33%), and limb anomalies (25%), in every possible combination. Three VACTERL subtypes were defined: STRICT-VACTERL, VACTERL-LIKE, and VACTERL-PLUS, based on severity and presence of additional congenital anomalies. Conclusion: The clearly defined VACTERL component features and the VACTERL subtypes introduced will improve both clinical practice and etiologic research.acceptedVersio