Overview of Health Issues in School-aged Children with Down Syndrome

Abstract

Background: School-aged children with Down syndrome experience an array of medical conditions and health care problems. Although there have been vast improvements in the medical management of these conditions, they still significantly impact on quality of life for families and children with Down syndrome. However, despite the magnitude of this problem limited literature has described the overall health status of children with Down syndrome.

Aim: The purpose of this review was to describe the medical conditions commonly experienced by school-aged children with Down syndrome and to consider the clinical implications of this knowledge.

Methods: Electronic searches of Medline, CINAHL, and PsychINFO and manual searches of reference lists identified relevant articles from 1990 to 2009. Studies were included if the topic involved one or more medical comorbidity and participants were children aged 18 years or younger with a diagnosis of Down syndrome. Articles were excluded at the title or abstract level if they were not peer-reviewed, in a language other than English, or did not meet the inclusion criteria. A narrative review of this research was possible.

Results: Common medical conditions experienced by school-aged children with Down syndrome include: heart disease; respiratory problems; gastrointestinal disorders; obesity; ophthalmological, ear, and hearing problems; musculoskeletal problems; leukemia and thyroid conditions; frequent infections; and dental disease. Prevalence estimates for these conditions varied depending on the diagnostic criteria or study methodologies.

Introduction

Down syndrome is a chromosomal birth disorder and the single most common cause of intellectual disability in Western Australia (Bower, Leonard, & Petterson, 2000). The worldwide prevalence of Down syndrome varies and may be determined by accessibility to prenatal screening (Weijerman et al., 2008), socio-cultural attitudes, religious beliefs, and political legislation regarding termination of pregnancy (Bittles, Bower, Hussain, & Glasson, 2006). Surveillance of congenital anomalies through population-based registries in Europe (Eurocat, 2010) reports birth prevalences of Down syndrome varying from 4.57 in the Czech Republic to 22.67 per 10,000 livebirths in Southern Ireland for the period 2004–2008 (Table 3.1). Total birth prevalence, including livebirths, terminations, fetal deaths/stillbirths over 20 weeks also varies from 12.86 in the Ukraine to 41.4 per 10,000 births in Paris, France. A review of prevalence of Down syndrome livebirths in the published literature representing birth years from 1967 to 2003 is shown in Table 3.2. The prevalence varies from a low of 2.18/10,000 livebirths in Taiwan (1993–2001) to a high of 17.2/10,000 livebirths in Ireland (1980–1989). Although there is ethnic variation, no clear temporal trends were evident from these data over these time periods.

In Western Australia, since 1980 the number of children born with Down syndrome has remained relatively stable at approximately 1 per 1000 births; however, the overall cases of Down syndrome conceptions (livebirths, stillbirths, and terminations of pregnancy) has more than doubled, from 1.2 per 1000 conceptions in 1980–84 to 2.6 per 1000 in 2006 (Bower, Callaghan, Cosgrove, & Quick, 2007). This change in the epidemiology of Down syndrome has been largely the result of increasing maternal age (Melve et al., 2008) and the widespread utilization of early prenatal screening (Besser, Shin, Kucik, & Correa, 2007).

It is well documented that Down syndrome is strongly correlated with maternal age (Sherman, Allen, Bean, & Freeman, 2007). Due to the changing roles of women in westernized societies, major socio-demographic shifts have resulted in increasing maternal age. Within the Australian context, women’s participation in the workforce has increased from 40% in 1979 to 55% in 2006 (Australian Bureau Statistics, 2006, Australian Bureau Statistics, 2009) and their educational attainment is now similar to that of men (Australian Bureau Statistics, 2007). As a result, the postponement of childbirth has contributed to the overall increase in Down syndrome conceptions (Bower et al., 2007).

The large increase in the reporting of Down syndrome conceptions is attributed to the accessibility and utilization of antenatal screening programs. In Australia, since 1999, the rate of women’s participation in antenatal screening programs has increased 2.5-fold to 44% (O’Leary, Breheny, Reid, Charles, & Emery, 2006) and the proportion of Down syndrome cases diagnosed prenatally for women under 35 has increased from 3 to 60% (Collins, Muggli, Riley, Palma, & Halliday, 2008). As a result, fetuses which would usually have spontaneously miscarried, are now being detected, contributing to an increase in the reporting of Down syndrome conceptions (Collins et al., 2008, Leonard, 2005). However, a corresponding increase in terminations of Down syndrome pregnancies has resulted in a relatively stable prevalence of Down syndrome livebirths (Bittles & Glasson, 2004). Rates of terminations are however influenced by countries’ differing legislation regarding termination of pregnancy and their societies’ socio-cultural beliefs (Bittles et al., 2006).

Developed countries have seen dramatic improvements in infant survival and overall life expectancy for people with Down syndrome. In Australia over the past 40 years, the average life expectancy of people with Down syndrome has increased from 18 to 60 years of age (Bittles & Glasson, 2004). Of particular significance is the improvement in infant survival whereby 91% of infants are expected to survive to 1 year and 85% to 10 years (Leonard, Bower, Petterson, & Leonard, 2000). These rates are comparable to other developed countries (Rasmussen et al., 2006, Viola and Rosano, 2005). Internationally, there are ethnic disparities with a seven-fold increase in the risk of infant mortality shown to be associated with black maternal race in the US, but only among infants without cardiac defects (Rasmussen et al., 2006). Within Australia, survival of Aboriginal children with Down syndrome is also significantly reduced compared to non-Aboriginal children (Leonard et al., 2000).

Several factors have contributed to improvements in the survival rates for children with Down syndrome. The most important of these has been surgical advances in the management of congenital heart disease (Viola & Rosano, 2005). In addition, improved accessibility to antibiotics and vaccinations have contributed to a decline in morbidity and improved life expectancy of people with Down syndrome (Bittles & Glasson, 2004). Changes in community and health professionals’ attitudes have also influenced health care accessibility and survival (Bittles & Glasson, 2004), whereby people with Down syndrome are now afforded a higher degree of equality in the health care system (Savulescu, 2001). Ethical debates still persist in relation to implementing policies of equality when accounting for limited resources (Savulescu, 2001). However, arguments for equality of access are supported by research which suggests that denying access of children with Down syndrome to surgical interventions such as cardiac surgery does not improve the efficiency of scarce health resources (Roussot, Lawrenson, Hewitson, Smart, & de Decker, 2006).

School-aged children with Down syndrome experience an array of medical conditions and health care problems. A summary of published prevalences of individual medical conditions in Down syndrome is presented in Table 3.3, showing, for example, a variation in the prevalence of congenital heart defects from 44 to 56% (46% in WA) and in hearing loss from 31 to 50% (10.5% in WA). Although there have been vast improvements in the medical management of these conditions leading to increased rates of infant and child survival (Leonard, 2005), these comorbidities still impact on quality of life for families and children. However, despite the magnitude of this problem only limited literature is available describing the overall health status of children with Down syndrome. Therefore, the objective of this narrative literature review is to describe the medical conditions commonly experienced by school-aged children with Down syndrome and to consider the clinical implications of this knowledge.