Changes in yearly birth prevalence rates of children with Down syndrome in the period 1986-2007 in the Netherlands

• Published in: Journal of intellectual disability research Vol. 55; no. 5; pp. 462 - 473
• Main Authors: de Graaf, G., Haveman, M., Hochstenbach, R., Engelen, J., Gerssen-Schoorl, K., Poddighe, P., Smeets, D., van Hove, G.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.05.2011; Wiley-Blackwell; Wiley Subscription Services, Inc
• Subjects: Antenatal; Biological and medical sciences; birth prevalence; Birth Rate; Child clinical studies; Childbirth; Childbirth & labor; Children; Children with disabilities; Chromosome aberrations; Developmental disorders; Down Syndrome; Down Syndrome - epidemiology; Down's syndrome; epidemiology; Foreign Countries; Humans; Incidence; Infant, Newborn; Learning disabilities; Maternal Age; Medical genetics; Medical sciences; Miscellaneous; Models, Statistical; Netherlands; Netherlands - epidemiology; Numbers; Pregnancy; Prenatal care; Prenatal Diagnosis - trends; Prevalence; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; theory-based dynamic model; Netherlands; Europe; Chromosomal aberration; Human; Social environment; Trisomy; Prevalence; Annual variation; Mental health; Aneuploidy; Down syndrome; Epidemiology; Retrospective; theory-based dynamic model; Theoretical model; birth prevalence; Dynamic model; Child; Public health
• ISSN: 0964-2633; 1365-2788
• DOI: 10.1111/j.1365-2788.2011.01398.x

Background  The Netherlands are lacking reliable national empirical data in relation to the development of birth prevalence of Down syndrome. Our study aims at assessing valid national live birth prevalence rates for the period 1986–2007. Method  On the basis of the annual child/adult ratio of Down syndrome diagnoses in five out of the eight Dutch cytogenetic centres, the national annual figures of the National Cytogenetic Network on total numbers of postnatal Down syndrome diagnoses were transformed into national figures on total numbers of postnatal Down syndrome diagnoses in newborn children only. In combination with the national annual data of the Working Group for Prenatal Diagnostics and Therapeutics on numbers of Down syndrome pregnancies not aborted after diagnosis, national figures on birth prevalence were constructed. Results  For the period 1986–2007, results based on the data of the cytogenetic centres are almost similar to the theory‐based model data of de Graaf et al., with a small discrepancy of approximately 4%. Down syndrome birth prevalence in the Netherlands shows an upward trend from around 11 per 10 000 births in the early 1990s to around 14 per 10 000 births nowadays. Conclusion  In spite of expansion of antenatal screening in the Netherlands, Down syndrome live birth prevalence has risen in the last two decades as a result of rising maternal age. This increase in Down syndrome birth prevalence is in contrast to studies from other European countries.