[Demographic characteristics of Down's syndrome in Navarra. Trends of pre and postnatal diagnosis for the period 1991-2009]. / Caracteristicas demograficas del sindrome de Down en Navarra. evolucion del diagnostico pre y postnatal durante el periodo 1991-2009.

This study describes the development of pre and postnatal diagnosis of sindrome de Down (SD) in the Autonomous Community of Navarre from 1991 to 2009 and assesses its preventive impact in the population, as well as to associated socio-demographic changes. In the absence of a prenatal diagnosis for DS, the change in maternal age from 1991 to 2009 would have caused a 50% increase in births with this disorder. However, the antenatal rate detection of DS increased from 15.8% in 1991-4 to 64.3% in 2006-9, giving rise to a decreasing incidence trend, not statistically significant, during the study period and to a higher mean age of mothers of live births with DS (32.75± 5,02 and 34.8±4,82 years during the first and second periods of the study, respectively). The proportion of young mothers (<35 years) of live births with DS was 66% in 1991-4 and 45% in 2006-9. Close to one fifth of the total population of pregnant women, however, did not want to go through a maternal screening test or amniocentesis. Seventeen per cent of all live births with DS had a positive screening test, but mothers decided to continue pregnancy. These results suggest that, despite the application of new and more sensitive prenatal screening tests, the incidence of DS may still be relatively high in our population, an important factor to be considered for future antenatal preventive programs and adequate postnatal care.

Características demográficas del síndrome de Down en Navarra. Evolución del diagnóstico pre y postnatal durante el periodo 1991-2009 / Demographic characteristics of Down´s syndrome in Navarra. Trends of pre and postnatal diagnosis for the period 1991-2009

Este estudio describe la evolución del diagnóstico pre y postnatal del síndrome de Down (SD) en la Comunidad Foral de Navarra desde 1991 a 2009 y analiza su impacto preventivo a nivel poblacional, así como los cambios asociadas a dicha cromosomopatía. En ausencia de diagnóstico prenatal del SD, el cambio en la edad materna desde 1991 a 2009 hubiera conllevado un aumento del 50% en el número de nacimientos con esta cromosomopatía. Sin embargo, el incremento de la tasa de detección prenatal (15,8% durante 1991-1994 y 64,3% entre 2006-2009) ha condicionado una ligera tendencia descendiente de su prevalencia al nacimiento, no estadísticamente significativa, y un aumento en la edad media de sus madres (32,75± 5,02 y 34,8±4,82 años en el primer y último periodos, respectivamente). El porcentaje de SD nacidos vivos, hijos de madres menores de 35 años, fue del 66% en 1991-2004 y del 45% en 2006-2009. Casi una quinta parte de las gestantes rechazaron el cribado bioquímico o la amniocentesis y un 17% de los nacimientos con SD tuvieron un resultado de cribado positivo, pero las madres decidieron continuar el embarazo. Estos resultados sugieren que, a pesar de implementar nuevos y más sensibles test de cribado, la incidencia del SD puede mantenerse relativamente alta en nuestra población, circunstancia a tener en cuenta tanto en la elaboración de los planes de prevención antenatal como de los de su cuidado postnatal (AU)

This study describes the development of pre and postnatal diagnosis of sindrome de Down (SD) in the Autonomous Community of Navarre from 1991 to 2009 and assesses its preventive impact in the population, as well as to associated socio-demographic changes. In the absence of a prenatal diagnosis for DS, the change in maternal age from 1991 to 2009 would have caused a 50% increase in births with this disorder. However, the antenatal rate detection of DS increased from 15.8% in 1991-4 to 64.3% in 2006-9, giving rise to a decreasing incidence trend, not statistically significant, during the study period and to a higher mean age of mothers of live births with DS (32.75± 5,02 and 34.8±4,82 years during the first and second periods of the study, respectively).The proportion of young mothers (<35 years) of live births with DS was 66% in 1991-4 and 45% in 2006-9. Close to one fifth of the total population of pregnant women, however, did not want to go through a maternal screening test or amniocentesis. Seventeen per cent of all live births with DS had a positive screening test, but mothers decided to continue pregnancy. These results suggest that, despite the application of new and more sensitive prenatal screening tests, the incidence of DS may still be relatively high in our population, an important factor to be considered for future antenatal preventive programs and adequate postnatal care (AU)