Accuracy of reporting abortions with Down syndrome in England and Wales: a data linkage study.

BACKGROUND: The number of abortions of fetuses with Down syndrome in England and Wales reported by the Department of Health (DH) differs from that reported by the National Down Syndrome Cytogenetic Register (NDSCR). The aim of this study was to investigate the reasons for this. METHODS: Abortions in 2011 and 2012 from DH were matched to those from NDSCR. The number of cases not reported to either source was estimated. RESULTS: An estimated 2240 abortions of fetuses with Down syndrome occurred in 2011/12; NDSCR estimated 2208 and DH 1100. One thousand and six abortions were identified in both data sets, including 145 (14%) which were not recorded by DH as having Down syndrome. Abortions in NDSCR that were not matched in DH occurred throughout England and Wales and at all gestational ages. An estimated 61 abortions of fetuses with Down syndrome were not reported to DH or NDSCR. CONCLUSIONS: The number of abortions of fetuses with Down syndrome reported by the NDSCR is more complete than that reported by the DH. DH data for abortions with other congenital anomalies are also likely to be underestimates, and more accurate estimates are available from BINOCAR regional congenital anomaly registers.

Down syndrome birth weight in England and Wales: Implications for clinical practice.

The aim of this study was to determine if syndrome-specific birth weight charts were beneficial for babies with Down syndrome in England and Wales. Birth weights of 8,825 babies with Down syndrome born in England and Wales in 1989-2010 were obtained from the National Down Syndrome Cytogenetic Register. Birth weight centiles for 30-42 weeks gestation by sex were fitted using the LMS method and were compared to those for unaffected babies from the UK-WHO growth charts. For babies born with Down syndrome the median birth weight from 37 to 42 weeks was 2,970 g (10th-90th centile: 2,115-3,680) for boys and 2930 g (2,100-3,629) for girls, and the modal age of gestation was 38 weeks, 2 weeks earlier than for unaffected babies. At 38 weeks gestation they were only slightly lighter than unaffected babies (159 g for boys and 86 g for girls). However at 40 weeks gestation the shortfall was much greater (304 g and 239 g, respectively). In neonates with Down syndrome there is little evidence of growth restriction before 38 weeks gestation, so up to this age it is appropriate to use the UK-WHO birth weight charts. Thereafter birth weight is below that of unaffected babies and it should be plotted on the UK Down syndrome growth charts.

Trends in congenital anomalies in Europe from 1980 to 2012.

BACKGROUND: Surveillance of congenital anomalies is important to identify potential teratogens. METHODS: This study analysed the prevalence of 61 congenital anomaly subgroups (excluding chromosomal) in 25 population-based EUROCAT registries (1980-2012). Live births, fetal deaths and terminations of pregnancy for fetal anomaly were analysed with multilevel random-effects Poisson regression models. RESULTS: Seventeen anomaly subgroups had statistically significant trends from 2003-2012; 12 increasing and 5 decreasing. CONCLUSIONS: The annual increasing prevalence of severe congenital heart defects, single ventricle, atrioventricular septal defects and tetralogy of Fallot of 1.4% (95% CI: 0.7% to 2.0%), 4.6% (1.0% to 8.2%), 3.4% (1.3% to 5.5%) and 4.1% (2.4% to 5.7%) respectively may reflect increases in maternal obesity and diabetes (known risk factors). The increased prevalence of cystic adenomatous malformation of the lung [6.5% (3.5% to 9.4%)] and decreased prevalence of limb reduction defects [-2.8% (-4.2% to -1.5%)] are unexplained. For renal dysplasia and maternal infections, increasing trends may be explained by increased screening, and deceases in patent ductus arteriosus at term and increases in craniosynostosis, by improved follow up period after birth and improved diagnosis. For oesophageal atresia, duodenal atresia/stenosis and ano-rectal atresia/stenosis recent changes in prevalence appeared incidental when compared with larger long term fluctuations. For microcephaly and congenital hydronephrosis trends could not be interpreted due to discrepancies in diagnostic criteria. The trends for club foot and syndactyly disappeared once registries with disparate results were excluded. No decrease in neural tube defects was detected, despite efforts at prevention through folic acid supplementation.

Occupational Exposure to Hydrazine and Subsequent Risk of Lung Cancer: 50-Year Follow-Up.

PURPOSE: Hydrazine is carcinogenic in animals, but there is inadequate evidence to determine if it is carcinogenic in humans. This study aimed to evaluate the association between hydrazine exposure and the risk of lung cancer. METHODS: The cause specific mortality rates of a cohort of 427 men who were employed at an English factory that produced hydrazine between 1945 and 1971 were compared with national mortality rates. RESULTS: By the end of December 2012 205 deaths had occurred. For men in the highest exposure category with greater than two years exposure and after more than ten years since first exposure the relative risks compared with national rates were: 0.85 (95% CI: 0.18-2.48) for lung cancer, 0.61 (95% CI: 0.07-2.21) for cancers of the digestive system, and 0.44 (95% CI: 0.05-1.57) for other cancers. CONCLUSIONS: After 50 years of follow up, the results provide no evidence of an increased risk of death from lung cancer or death from any other cause.

Antenatal detection of Edwards (Trisomy 18) and Patau (Trisomy 13) syndrome: England and Wales 2005-2012.

OBJECTIVES: Pregnancies with Edwards or Patau syndrome are often detected through screening for Down's syndrome. We aimed to evaluate the impact of screening for Down's syndrome on the prevalence of live births and antenatal diagnoses of Edwards and Patau syndrome. SETTING: England and Wales, 2005 to 2012. METHODS: Data from the National Down Syndrome Cytogenetic Register, which contains information on nearly all ante- or postnatally diagnosed cases of Edwards or Patau syndrome in which a karyotype was confirmed, were analysed. RESULTS: From 2005 to 2012, 3,941 diagnoses of Edwards syndrome and 1,567 diagnoses of Patau syndrome were recorded (prevalence of 7.0 and 2.8 per 10,000 births respectively). Only 11% (95% confidence interval [CI]: 10-12) of diagnoses of Edwards syndrome and 13% (95% CI: 11-14) of Patau syndrome were live births, resulting in live birth prevalences of 0.8 (95% CI: 0.7-0.8) and 0.4 (95% CI: 0.3-0.4) per 10,000 live births respectively. About 90% of pregnancies with Edwards or Patau syndrome were diagnosed antenatally, and this proportion remained constant over time. The proportion of diagnoses detected before 15 weeks increased from 50% in 2005 to 53% in 2012 for Edwards syndrome, and from 41% in 2005 to 63% in 2012 for Patau syndrome. CONCLUSIONS: Almost 700 women per year had a pregnancy with Edwards or Patau syndrome. Over 90% of these pregnancies were detected antenatally, with the increased use of first trimester screening for Down's syndrome resulting in the reduction in the mean gestational age at diagnosis of these syndromes.