Frecuencia de los defectos del tubo neural en Asturias: impacto del diagnóstico prenatal

objective: to describe the frequency and prevalence trend for neural tube defects (ntd) (anencephaly, spina bifida and encephalocele) in asturias (spain), as well as the impact of prenatal diagnosis programs. methods: all cases of ntd in births and induced abortions were studied, using data from the registry of congenital defects of asturias for 1990-2004. total and birth prevalence rates were calculated. results: the prevalence of ntd for 1990-2004 was 12.2 per 10,000 births (5.9 anencephaly, 5.0 spina bifida and 1.3 encephalocele) and showed a slightly decreasing trend due to a significant decline in spina bifida prevalence. the prevalence of anencephaly and encephalocele remained stable. the percentage of induced abortions after prenatal diagnosis among all ntd was 88% (anencephaly 96.7%, spina bifida 80% and encephalocele 84.6%), leading to a very low birth prevalence (1.4 per 10,000) for the entire period. conclusions: the total prevalence of spina bifida has decreased in the last 15 years in asturias. secondary prevention through prenatal diagnosis and interruption of affected pregnancies have resulted in a marked decrease in ntd at birth. the recommendation of periconceptional use of folic acid seems not to have achieved the desired effect.