A Busby

Preventing neural tube defects in Europe: population based study

Each year, more than 4500 pregnancies in the European Union are affected by neural tube defects. Unambiguous evidence of the effectiveness of periconceptional folic acid in preventing neural tube defects has been available since 1991,1 and improving folate status sufficiently could result in the prevention of more than two thirds of all neural tube defects. We report on trends in the prevalence of neural tube defects up to 2001, in the context of a survey in 16 European countries of periconceptional folic acid policies and their implementation.2 3 Eurocat is a network of population based congenital anomaly registries in Europe (http://www.eurocat.ulster.ac.uk/). A total of 9 273 212 births were surveyed by 31 registries in 16 countries 1980-2001,3 including 8913 babies or fetuses with neural tube defects (anencephaly, spina bifida, or encephalocele): 3298 live births, 844 stillbirths, and 4771 terminations of pregnancy after prenatal diagnosis. In the United Kingdom and Ireland, yearly prevalence of neural tube defects declined, predating any periconceptional folic acid supplementation policy initiatives, from 45 per 10 000 births in 1980 to 10 to 15 per 10 000 in the 1990s (%figure). In contrast, in the rest of Europe the prevalence during the 1980s and thereafter was close to 10 per 10 000 …

Geographical variation in anophthalmia and microphthalmia in England, 1988-94.

Abstract Objective: To investigate the geographical variation and clustering of congenital anophthalmia and microphthalmia in England, in response to media reports of clusters. Design: Comparison of pattern of residence at birth of cases of anophthalmia and microphthalmia in England in 1988-94, notified to a special register, with pattern of residence of all births. Three groups studied included all cases, all severe cases, and all severe cases of unknown aetiology. Outcome measures: Prevalence rates of anophthalmia and microphthalmia by region and district, and by ward population density and socioeconomic deprivation index of enumeration district grouped into fifths. Clustering expressed as the tendency for the three nearest neighbours of a case to be more likely to be cases than expected by chance, or for there to be more cases within circles of fixed radius of a case than expected by chance. Results: The overall prevalence of anophthalmia and microphthalmia was 1.0 per 10 000 births. Regional and district variation in prevalence did not reach statistical significance. Prevalence was higher in rural than urban areas: the relative risk in the group of wards of lowest population density compared with the most densely populated group was 1.79 (95% confidence interval 1.15 to 2.81) for all cases and 2.37 (1.38 to 4.08) for severe cases. There was no evidence of a trend in risk with socioeconomic deprivation. There was very little evidence of localised clustering. Conclusions: There is very little evidence to support the presence of strongly localised environmental exposures causing clusters of children to be born with anophthalmia or microphthalmia. The excess risk in rural areas requires further investigation.

Outdoor air pollution and infant mortality: analysis of daily time-series data in 10 English cities

Background: There is growing concern that moderate levels of outdoor air pollution may be associated with infant mortality, representing substantial loss of life-years. To date, there has been no investigation of the effects of outdoor pollution on infant mortality in the UK. Methods: Daily time-series data of air pollution and all infant deaths between 1990 and 2000 in 10 major cities of England: Birmingham, Bristol, Leeds, Liverpool, London, Manchester, Middlesbrough, Newcastle, Nottingham and Sheffield, were analysed. City-specific estimates were pooled across cities in a fixed-effects meta-regression to provide a mean estimate. Results: Few associations were observed between infant deaths and most pollutants studied. The exception was sulphur dioxide (SO2), of which a 10 μg/m3 increase was associated with a RR of 1.02 (95% CI 1.01 to 1.04) in all infant deaths. The effect was present in both neonatal and postneonatal deaths. Conclusions: Continuing reductions in SO2 levels in the UK may yield additional health benefits for infants.

Eye anomalies: seasonal variation and maternal viral infections.

Introduction: Eye anomalies, including anophthalmos and microphthalmos (absent eye and small eye), are common features in congenital infection syndromes such as rubella. Influenza, Coxsackie virus, and Parvovirus are less well-established teratogens. We report an ecologic analysis of anophthalmia/microphthalmia prevalence in England in relation to temporal variation in these infections using routine infection data. Methods: The national (England) anophthalmos/microphthalmos register holds details of 406 babies (excluding chromosomal anomalies) born 1988–1994. Weekly infection data were obtained from the U.K. Public Health Laboratory Service and Royal College of General Practitioners Weekly Returns Service. We assigned cases and births an estimated exposure based on the population infection counts in the gestational weeks known to be critical for ocular development. We calculated the rate ratio of anophthalmos/microphthalmos prevalence for infection in the 90th percentile compared with the 10th percentile by Poisson regression. Results: There was a positive association between severe anophthalmos/microphthalmos prevalence and Parvovirus B19 (rate ratio = 1.26; 95% confidence interval = 1.00–1.58) and for influenza (1.41; 1.08–1.84). Coxsackie virus showed a negative association with any anophthalmos/microphthalmos (0.75; 0.58–0.98) and with severe cases (0.66; 0.46–0.95). Conclusions: This analysis provides suggestive evidence for a teratogenic role of influenza and Parvovirus in anophthalmos/microphthalmos. The role of maternal infections in congenital anomaly etiology is worthy of further investigation.