<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0001-6002</journal-id>
<journal-title><![CDATA[Acta Médica Costarricense]]></journal-title>
<abbrev-journal-title><![CDATA[Acta méd. costarric]]></abbrev-journal-title>
<issn>0001-6002</issn>
<publisher>
<publisher-name><![CDATA[Colegio de Médicos y Cirujanos de Costa Rica]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0001-60022019000400177</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Prevalencia al nacimiento de síndrome de Down, según edad materna en Costa Rica, 1996-2016]]></article-title>
<article-title xml:lang="en"><![CDATA[Birth prevalence of Down syndrome according maternal age in Costa Rica, 1996-2016]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Benavides-Lara]]></surname>
<given-names><![CDATA[Adriana]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Barboza-Argüello]]></surname>
<given-names><![CDATA[María de la Paz]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Instituto Costarricense de Investigación y Enseñanza en Nutrición y Salud (INCIENSA) Unidad de Enfermedades Congénitas (UEC), Centro de Registro de Enfermedades Congénitas (CREC),]]></institution>
<addr-line><![CDATA[Cartago ]]></addr-line>
<country>Costa Rica</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>12</month>
<year>2019</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>12</month>
<year>2019</year>
</pub-date>
<volume>61</volume>
<numero>4</numero>
<fpage>177</fpage>
<lpage>182</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.sa.cr/scielo.php?script=sci_arttext&amp;pid=S0001-60022019000400177&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.sa.cr/scielo.php?script=sci_abstract&amp;pid=S0001-60022019000400177&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.sa.cr/scielo.php?script=sci_pdf&amp;pid=S0001-60022019000400177&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen  Justificación: El síndrome de Down es la cromosomopatía más frecuente en Costa Rica y el mundo, así como la principal causa de discapacidad intelectual. La edad materna avanzada es el mayor factor de riesgo conocido para este padecimiento. El objetivo fue conocer la tendencia de síndrome de Down en nacidos vivos, según edad materna en Costa Rica.  Métodos: Se realizó un estudio observacional de prevalencias de todos los casos de síndrome de Down nacidos vivos en Costa Rica entre 1996-2016, reportados al Centro Nacional de Registro de Enfermedades Congénitas, programa nacional de vigilancia de los defectos congénitos. Se determinó la tendencia y prevalencia en nacidos vivos según edad materna: &lt; 20, 20-34 y 35 años o más, y según período: 1996-2007 y 2008-2016. Se realizó una regresión de Poisson, tomando como referencias el grupo 20-34 años y 1996-2002, y se compararon estimados mediante chi cuadrado de Wald. Se calculó la razón de prevalencias en madres &#8805;35 años y la fracción atribuible poblacional para este estrato. Por último, se comparó la tendencia del síndrome de Down con la tendencia de la tasa de fecundidad específica en madres &#8805;35 años en el país, para el período en estudio.  Resultados:  Para 1996-2016, la prevalencia de síndrome de Down en nacidos vivos fue de 1,02 x 1000 (IC95 %: 0,97-1,07). Hubo un aumento significativo de 0,91 (1996-2007) a 1,16 x 1000 (2008-2016), a expensas de la prevalencia en madres &#8805;35 años, la cual aumentó de 4,27 a 5,44 x 1000; mientras que la tasa de fecundidad en estas madres cayó significativamente de 20,15 x 1000 (IC95 %: 20,02-20,28) en 1996-2007, a 15,58 x 1000 (IC95 % 15,46-15,70) para o 2008-2016. La edad materna media en SD fue de 32,2 años, contra 25,5 años para la población general (p&#8804;0,001). La razón de prevalencia ajustada por período, en madres de &#8805;35 años, contra madres de 20-34 años fue de 8,05 (IC95 % 7,25-8,95) y la fracción atribuible poblacional del 41,22 %.  Conclusiones: La prevalencia al nacimiento de síndrome de Down en Costa Rica aumentó a expensas de la prevalencia en madres &#8805;35 años, pese a que la tasa de fecundidad específica en esas mujeres cayó significativamente. La inclusión del Hospital Nacional de Niños como institución de referencia nacional para este síndrome, dentro de la red de vigilancia de los defectos congénitos, pudo ser un factor determinante en el aumento de la prevalencia.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract  Justification:  Down syndrome is the most frequent chromosomopathy in Costa Rica and the world, as well as the main cause of intellectual disability. Advanced maternal age is the main known risk factor for this condition. The objective was to know the trend of Down syndrome in live births according to maternal age in Costa Rica.  Methods:  A prevalence study was made of all Down syndrome cases, born alive in Costa Rica from 1996 to 2016 and reported to the Costa Rican Births Defects Register Center, a national program for the monitoring of congenital defects. The trend and prevalence in live births was determined, according to maternal age: &lt;20, 20-34 and 35 years or more, and according to period: 1996-2007 and 2008-2016. A Poisson regression was carried out, taking as references the group 20-34 years and the period 1996-2002 and the results were compared Wald&#8217;s chi-square. The prevalence ratio in mothers &#8805;35 years and the population attributable fraction was calculated for this stratum. Finally, the trend of Down syndrome was compared with the trend of the specific fertility rate in mothers &#8805;35 years.  Results:  For 1996-2016 the prevalence of Down syndrome in live births was 1.02 x 1000 (95% CI: 0.97-1.07). There was a significant increase from 0.91 (1996-2007) to 1.16 x 1000 (2008-2016), at the expense of the prevalence in mothers &#8805;35 years, which increased from 4.27 to 5.44 x 1000; while the fertility rate in these mothers fell significantly from 20.15 x 1000 (95% CI: 20.02-20.28) in 1996-2007, to 15.58 x 1000 (95% CI 15.46-15.70) in 2008-2016. Maternal age mean MS in SD was 32.2 years, versus 25.5 years in the general population (p&#8804;0.001). The prevalence ratio adjusted by period, in mothers of &#8805;35 years, against mothers of 20-34 years was of 8.05 (95% CI 7.25-8.95) and the population attributable fraction was 41.22%.  Conclusions:  The livebirth`s prevalence of Down syndrome in Costa Rica increased for the study period, at the expense of prevalence in mothers &#8805;35 years, although the specific fertility rate in these women fell significantly. The inclusion of the National Children&#8217;s Hospital - as a national reference institution for this syndrome - within the surveillance network of congenital defects, could be a determining factor in in prevalence rise.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[síndrome de Down]]></kwd>
<kwd lng="es"><![CDATA[epidemiología]]></kwd>
<kwd lng="es"><![CDATA[edad materna]]></kwd>
<kwd lng="es"><![CDATA[prevalencia]]></kwd>
<kwd lng="en"><![CDATA[Down syndrome]]></kwd>
<kwd lng="en"><![CDATA[epidemiology]]></kwd>
<kwd lng="en"><![CDATA[maternal age]]></kwd>
<kwd lng="en"><![CDATA[prevalence]]></kwd>
</kwd-group>
</article-meta>
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