Evidence for changing guidelines for routine screening for retinopathy of prematurity

CONTEXT: Existing guidelines recommended by the Canadian Pediatric Society (CPS) and American Academy of Pediatrics (AAP) for routine screening for retinopathy of prematurity (ROP) remain controversial. OBJECTIVE: To determine whether current guidelines for routine screening for ROP should be changed. DESIGN: We examined data that were collected as part of a larger study of 14 neonatal intensive care units (NICUs) in Canada. We examined the effect of strategies using different birth weight (BW) and gestational age (GA) criteria for routine ROP screening, and performed a cost-effectiveness analysis. SETTING: The 14 NICUs (except one) are regional tertiary level referral centres serving geographic regions of Canada, and include approximately 60% of all tertiary-level NICU beds in Canada. PATIENTS: This large cohort included all 16 424 infants admitted to 14 Canadian NICUs from January 8, 1996, to October 31, 1997. INTERVENTIONS: None. MAIN OUTCOME MEASURE: Treatment for ROP. RESULTS: The most cost-effective strategy was to routinely screen only infants having a BW of 1200 g or less. This included all infants treated for ROP (except 1 outlier at 32 weeks GA and 1785 g BW), at a marginal cost per additional person with improved vision of $513 081 for screening patients between 28 weeks GA and 1200 g BW, compared with $1 800 039 and $2 075 874 for using the current AAP and CPS guidelines, respectively (cryotherapy outcomes). Results for laser therapy were similar, but costs were slightly lower. This strategy reduced the number of infants screened under the current CPS guidelines by 46%. CONCLUSION: Screening only infants having a BW of 1200 g or less is the most cost-effective strategy for routine ROP screening.     

Evidence for newborn screening for cystic fibrosis

Different strategies are available for studying the effectiveness of newborn screening for cystic fibrosis (CF). Although observational studies suggest clinical benefits, their results are difficult to interpret because of the potential for several methodological problems. Randomised studies show that age at time of diagnosis is an important factor in the nutritional status of pancreatically insufficient patients and that a delayed diagnosis increases the risk of malnutrition in childhood. Effects on lung disease are more controversial. Advantages other than better clinical outcome or survival may be obtained by the implementation of CF neonatal screening, mainly the opportunity for presymptomatic trials and treatments and more informed reproductive choices for parents and relatives. Disadvantages of neonatal screening for CF include the detection of heterozygotes and the discovery of mild forms of disease.     

A new method for screening for hyperammonemia

A new method for the detection of hyperammonemia, using a kit based on the principle of microdiffusion of ammonia, is described. The method requires only one drop of blood and takes only 15 min to complete. Experiments for recovery and reproducibility were satisfactory, and good correlation was obtained when compared with an enzymatic method for blood ammonia determination. The new method is considered to be useful for routine, low-cost mass-screening of newborn infants for hyperammonemia. It will also be useful for monitoring blood ammonia levels at the bedside in cases with hepatic disease or receiving parenteral nutrition.     

Prospects for gene therapy for inherited cardiomyopathies

Over the last few years the genes responsible for a number of genetic diseases of the cardiovascular system have been identified. These have included X-linked and autosomal dominant dilated cardiomyopathy, and hypertrophic cardiomyopathy. Genetic heterogeneity has been described in both of these diseases but a commonality of function has been apparent: defects in cytoskeletal proteins cause dilated cardiomyopathy and mutations in sarcomeric proteins cause hypertrophic cardiomyopathy. This led us to develop a 'final common pathway' hypothesis as a framework for selecting candidate genes for mutation screening in families with these diseases. The characterization of gene mutations has led to the development of therapies specifically targeting the defective protein or the pathway in which it is involved. These have included the use of pharmaceutical agents to replace or to antagonize the mutated protein, and replacement of the defective gene with a functional one (gene therapy). While early studies using gene therapy vectors were promising, translating studies in animals to viable therapeutic options for humans has remained problematic. There have been many publications describing the use of vectors to transduce target cells for the correction of gene defects, including recombinant retroviruses, adenoviruses, and adeno-associated viruses, as well as non-viral vectors. In this review we will discuss the identification of gene defects associated with cardiomyopathies, and the potential of gene therapy for the treatment of these diseases, as well as addressing some concerns related to the use of adenovirus-based vectors, a virus known to be an etiologic agent of acquired dilated cardiomyopathy.     

Risk factors for small for gestational age

BACKGROUND: The purpose of the paper was to determine the risk factors for small-for-gestational-age (SGA) infants at full term, in Japan. METHODS: The study was conducted at four hospitals and clinics in the Tokyo metropolitan area. A retrospective review of 2972 mothers and their infants born from singleton pregnancies at any time during the years 2002 and 2003 was conducted. RESULTS: Of these women, 8.4% gave birth to SGA infants. The proportion of SGA infants was significantly higher among heavy smokers (>10 cigarettes/day; 13.7%, P < 0.01). The odds ratio (OR) for SGA decreased significantly in proportion to the pregnancy body mass index (OR, 0.89; 95% confidence interval [CI]: 0.84-0.94, P < 0.001). The OR of SGA for stratified maternal weight gain was 1.79 (95%CI: 1.24-2.58, P 12 kg. CONCLUSION: The present study clearly confirms the detrimental effect of a low prepregnancy body mass index, low maternal weight gain and maternal smoking during pregnancy on the incidence of SGA infants.     

Call for a national plan for rare diseases

Australia requires a national plan, similar to plans developed internationally, to address the impacts of rare diseases on individuals, the community and health services. Rare diseases often present in childhood, many are chronic, some life threatening and others associated with significant disability. However, diagnosis is often delayed, because of lack of knowledge and experience of health professionals and uncertainty about where to refer. Specialised health services are frequently lacking and specific therapies are often not available, partly because of lack of research funding directed towards rare diseases. A national plan would facilitate a coordinated response to service development, carer support, and health professional and community education, and would promote research and advocacy for affected children and their families.