Outcome in Down syndrome fetuses with cardiac anomalies

Wehave readwith interest thearticle byWessels et al. [2003] recently published in your journal on the outcome in Down syndrome fetuses. This article reports the poor prognosis of fetuses with Down syndrome and cardiac defects: combining spontaneous intrauterine deaths and deaths in the first year of life, the mortality of 30 subjects with trisomy 21 cases was as high as 60%. Moreover among the 20 live born patients with Downsyndrome, cardiac defect and/or small for gestational age there were eight deaths in the first year of life (40%). In our opinion these figures may be misleading and are of little help to health care providers to answer the many questions of the trisomy 21 subjects’ families. When, in a fetus around 20 weeks of gestation, the diagnosis of Down syndrome is made the first question is: what is the probability of surviving up to the birth? The answer to this question has been given byHook et al. [1995]. It depends on the gestational age at the diagnosis and figures are precisely given by the authors for this variable. For example, at 18 weeks the survival probability is 69% and at 22 it is 76%. The second important question is: is the probability of survival different inDownsyndrome subjectswith orwithout a cardiac defect? From the Wessel’s study, we cannot have a reasonable answer since the study sample is too small and biased as the authors pointed out. Furthermore, from their available data it seems that the presence of a congenital heart defect (CHD) is, paradoxally, a protective factor for up to term survival. The ratio for survival with CHD versus without CHD1⁄4 1.35 (95% CI: 0.74–2.47) (Table I). Survival of persons with Down syndrome has improved in the last 20–30 years for those with and without CHD. Nowadays the majority of available data reported from developed countries suggests a 1-year and 5-years survival, respectively of 95% and 90% [Mastroiacovo et al., 2002]. These data suggest that the overall life tableup toadult agepublishedbyBairdand Sadovnick [1989], is the best estimate that can be used by a health care provider. For example, from this study the median survival (the age at which 50% of subjects are expected to die) can be estimated to be 58 years. Actually, this is an overall figure. What about survival of persons with and without CHD? Among the many studies addressing this question [Baird and Sadovnick, 1987; Malone, 1988; Mathew et al., 1990; McGrother and Marshall, 1990; Mikkelsen et al., 1990; Mastroiacovo et al., 1992; Brookes and Alberman, 1996; Hayes et al., 1997; Hijii et al., 1997; Castilla et al., 1998; Frid et al., 1999; Malek et al., 1999; Leonard et al., 2000] only three of them are population-based, had an unbiased ascertainment of CHD, have been performed in a developed country and on a recent cohort. In these three studies [Hayes et al., 1997; Frid etal. , 1999;Leonardetal. , 2000], thesurvival estimateat1year is around 85% compared with an estimate around 95% for infants without CHD. The 10% difference in survival between those without CHD and those with CHD is similar also in another study performed in south America [Castilla et al., 1998]. Another important finding suggested by some studies is that the survival of operated children is very similar to that of children without CHD [Hayes et al., 1997; Hijii et al., 1997]. Moreover, the last piece of information useful for the health care provider, is that Down syndrome is no longer considered a risk factor for surgical correction of CHD [Schneider et al., 1989; Vet and Ottenkamp, 1989; Rizzoli et al., 1992]. More specifically, in patients with atrioventricular canal, the most frequent cardiac defect in children with trisomy 21, the early and late surgical prognosis of the subjects with Down syndrome seems to be better if compared with those of nonDown patients [Di Carlo and Marino, 1994; Giamberti et al., 1996; Boening et al., 2002; Al-Hay et al., 2003]. This fact is due to a better anatomic pattern of heart defect in children with Down syndrome [De Biase et al., 1986; Giamberti et al., 1996; Al-Hay et al., 2003]. In conclusion, we believe that the poor prognosis recorded by Wessels et al. [2003], does not reflect the current data of the literature and does not modify the current knowledge that Down syndrome infants, with or without CHD, have reached a quite good survival rate, especially in comparison with the past.