[Prevalence and secular trend of congenital defects in Asturias, Spain. The need for clinical-epidemiological surveillance].

OBJECTIVE Congenital defects remain the second cause of perinatal and infant death and the third cause between the second and fifth years of life in Asturias. These anomalies generate substantial morbidity. The aim of the present study was to describe the population-based frequency of congenital defects in Asturias and their forms of presentation. METHODS Data from the population-based Registry of Congenital Defects of Asturias for 1990-2004 were analyzed. The data related to live births, stillbirths and induced abortions after prenatal diagnosis and are presented as birth prevalence and total prevalence (including induced abortions). RESULTS The total number of births was 103,452 and there were 3,035 cases of congenital defects, representing a total prevalence of 2.9 cases per 100 births and a birth prevalence of 2.5%. These figures showed a tendency to increase throughout the study period. A total of 2,516 (82.9%) cases were live births, 46 (1.5%) were stillbirths and 473 (15.6%) were induced abortions. Prenatal diagnosis increased throughout the period. Sixtythree percent of total cases showed an isolated defect, 17% a recognized syndrome and the remaining 20% had multiple malformations without a syndromic pattern. The most frequent and severe defects registered were neural tube defects (12.2 per 10,000 births), chromosomal abnormalities (34.4 per 10,000), and cardiac defects (75.2 per 10,000). CONCLUSIONS The 15-year experience of the Registry of Congenital Defects of Asturias reveals the utility of this type of database to evaluate prenatal screening programs, plan the resources needed in affected pregnant women and infants, and perform epidemiological surveillance of congenital defects in relation to environmental risks, drug exposure and assisted reproduction techniques.