Prevalencia de defectos del tubo neural y estimación de casos evitados posfortificación en Argentina / Prevalence of neural tube defects and estimation of cases averted in the post-fortification period in Argentina

La ingesta periconcepcional de ácido fólico ha demostrado ser efectiva en la reducción de la frecuencia de defectos del tubo neural, y la fortificación de los alimentos ha sido una estrategia para incrementarla. Se presenta una actualización de la reducción de las prevalencias de defectos del tubo neural posfortificación en Argentina y la estimación de los casos evitados en el período 2005-2013 como consecuencia de esta intervención. Al comparar la prevalencia observada en el período posfortificación con la reportada en el período de prefortificación, se observa un descenso significativo de 66% para anencefalia y encefalocele, y de 47% para espina bífida. El número de casos evitados estimados fue mayor para anencefalia, seguido por espina bífida; encefalocele presentó el menor número de casos evitados, dado que la prevalencia de este defecto fue menor. El descenso de la prevalencia observado apoya los resultados de estudios previos sobre el efecto de la fortificación.

Periconceptional intake of folic acid has demonstrated to be effective to reduce the frequency of neural tube defects, and food fortification has been one of the strategies implemented to increase it. An update is herein presented on the reduced prevalence of neural tube defect cases in the post-fortification period in Argentina and an estimation of cases averted in the 2005-2013 period as a result of this intervention. When comparing the prevalence observed in the post-fortification period to that reported in the pre-fortification period, anencephaly and encephalocele decreased by 66%, and spina bifida, by 47%, which were significant reductions. The estimated number of cases averted was higher for anencephaly, followed by spina bifida; encephalocele showed the lowest number of cases averted given that the prevalence of this defect was smaller. The decrease observed in the prevalence supports findings from previous studies on the impact of fortification.

[Prevalence of neural tube defects and estimation of cases averted in the post-fortification period in Argentina]. / Prevalencia de defectos del tubo neural y estimación de casos evitados posfortificación en Argentina.

Periconceptional intake of folic acid has demonstrated to be effective to reduce the frequency of neural tube defects, and food fortification has been one of the strategies implemented to increase it. An update is herein presented on the reduced prevalence of neural tube defect cases in the post-fortification period in Argentina and an estimation of cases averted in the 2005-2013 period as a result of this intervention. When comparing the prevalence observed in the post-fortification period to that reported in the pre-fortification period, anencephaly and encephalocele decreased by 66%, and spina bifida, by 47%, which were significant reductions. The estimated number of cases averted was higher for anencephaly, followed by spina bifida; encephalocele showed the lowest number of cases averted given that the prevalence of this defect was smaller. The decrease observed in the prevalence supports findings from previous studies on the impact of fortification.

La ingesta periconcepcional de ácido fólico ha demostrado ser efectiva en la reducción de la frecuencia de defectos del tubo neural, y la fortificación de los alimentos ha sido una estrategia para incrementarla. Se presenta una actualización de la reducción de las prevalencias de defectos del tubo neural posfortificación en Argentina y la estimación de los casos evitados en el período 2005-2013 como consecuencia de esta intervención. Al comparar la prevalencia observada en el período posfortificación con la reportada en el período de prefortificación, se observa un descenso significativo de 66% para anencefalia y encefalocele, y de 47% para espina bífida. El número de casos evitados estimados fue mayor para anencefalia, seguido por espina bífida; encefalocele presentó el menor número de casos evitados, dado que la prevalencia de este defecto fue menor. El descenso de la prevalencia observado apoya los resultados de estudios previos sobre el efecto de la fortificación

Descriptive study on neural tube defects in Argentina.

BACKGROUND: Neural tube defects (NTDs) are the most common congenital anomalies of the central nervous system. Prevalence of NTDs varies depending on geographic region and folic acid fortification. The main objectives of this study are to analyze the prevalences of NTDs reported to the National Registry of Congenital Anomalies of Argentina (RENAC) during the period 2009 to 2013, to compare them with data from other selected surveillance systems of the Americas, and to evaluate the impact of folic acid fortification on the prevalence of NTDs in Argentina. METHODS: We analyzed changes in prevalence between 2009 and 2013 for the RENAC, and differences in prevalence between RENAC and other surveillance systems. We evaluated changes for the pre and postfortification time periods in Argentina. RESULTS: In Argentina, anencephaly and spina bifida showed no statistically significant variation between 2009 and 2013, and encephalocele showed a statistically significant decline. The RENAC showed a statistically significant higher prevalence for all three defects when compared with surveillance systems from Chile, Colombia, and Costa Rica, and a statistically significant lower birth prevalence than Cuba for anencephaly. No differences were observed when comparing it to the Atlanta-USA and Mexico systems. A significant decrease in prevalence was observed for all three anomalies for the postfortification period in Argentina. CONCLUSION: The characteristics of cases reported to the RENAC are similar to those already reported in the literature. The differences in prevalence between the RENAC and other surveillance systems could be artifactual or real. We confirmed the decrease of prevalence of NTDs after folic acid fortification.

The use of a Toolkit for health needs assessment on neural tube defects in Argentina.

Health needs assessment (HNA) is a commonly used process for those working in public health. The PHG Foundation has developed a Toolkit to provide users with a stepwise approach for undertaking a HNA on birth defects. We report the findings from using the Toolkit to examine needs in relation to policies and programs, services, and interventions for neural tube defects (NTDs) in Argentina. The trend over the last few decades is one of decline in infant mortality from nutritional and infectious causes, thus further increasing the relative importance of birth defects. The observed prevalence of NTDs is consistent with that reported internationally. Since 2002 folic acid fortification (FAF) has been mandatory by law, and different studies have shown at least a 50 % decrease in the birth prevalence of NTDs after FAF. In Argentina, there is inequity between the public and non-public health sectors. The birth prevalence of NTDs seems lower in the non-public sector, possibly as a result of better nutritional status of women, higher access to folic acid supplementation, and earlier prenatal diagnosis followed by termination of pregnancy (ToP) in non-public hospitals. Although illegal, ToP is believed to be widespread, with better access for people of higher socioeconomic status. Through the process of HNA, we identified several unmet needs regarding registration of cases, public and professional education, legislation, and organization of care pathways. In our experience, the Toolkit brought together people working on the same issue, and it engaged and motivated experts and stakeholders to work together to tackle the problem.