Elsevier

The Journal of Pediatrics

Volume 152, Issue 1, January 2008, Pages 20-24.e1
The Journal of Pediatrics

Original article
Is Down Syndrome a Disappearing Birth Defect?

https://doi.org/10.1016/j.jpeds.2007.07.045Get rights and content

Objective

To assess trends in the prevalence of Down syndrome (DS) from 1986 to 2004 in Victoria, Australia (population ∼5 million).

Study design

The Victorian Birth Defects Register and the Prenatal Diagnosis Database were linked to ascertain all cases of DS. Total and birth prevalence estimates were calculated per year and presented as 3-year moving averages.

Results

The total number of cases of DS increased from 113 in 1986 to 188 in 2004. The number of births declined over the first decade of the study, particularly in younger women, but total numbers have fluctuated between 45 and 60 births since 1996. In women under age 35 years, total prevalence was 10/10,000 until 1997 and then increased to 12.5/10,000. In older women, total prevalence increased from 70/10,000 to 90/10,000 in this time frame. Birth prevalence declined at first but remained relatively stable in the later years of the study. The proportion of cases diagnosed prenatally increased from 3% to 60% in younger women.

Conclusions

Our findings demonstrate the continuing need to devote resources to support individuals with DS and their families.

Section snippets

Databases

Two statewide data collections were used to ascertain all cases of DS in Victoria for the years 1986 to 2004. Access to these data was formally granted by the Consultative Council on Obstetric and Paediatric Mortality and Morbidity of Victoria.

The Births Defects Register (BDR) is a statewide population-based surveillance system administered by the Perinatal Data Collection Unit (PDCU) of the Victoria Department of Human Services. Notifications to the BDR come from multiple sources on all birth

Results

Figure 1 shows that against a relatively stable birth rate in Victoria, particularly since 1996, the total number of cases of DS increased from 113 in 1986 to a peak of 192 in 2002. Since 1996, the number of live births has generally been lower and the numbers of pregnancy termination pregnancy higher than in the earlier period.

Among the total cases of DS, the vast majority (97%) were trisomy 21. Over the 19-year study period, there were 72 cases of translocation DS, 85% of which occurred in

Discussion

This comprehensive analysis of the epidemiology of DS provides essential information for various stakeholders. The data can be used by policy makers and service providers to assess current programs and prioritize resources for the provision of prenatal testing programs. Importantly, the data highlight the ongoing need for support services for people with DS and their families. In addition, accurate current information is vital for consumer and support groups, such as the Down Syndrome

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    Supported by Australian National Health and Medical Research Council Research Fellowship 436904 (to J.H.).

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