Our aim was to provide a descriptive overview of how the birth defects surveillance and folic acid fortification programs were implemented in Costa Rica—through the establishment of the Registry Center for Congenital Anomalies (Centro de Registro de Enfermedades Congénitas—CREC), and fortification legislation mandates. We estimated the overall prevalence of neural tube defects (i.e., spina bifida, anencephaly and encephalocele) before and after fortification captured by CREC. Prevalence was calculated by dividing the total number of infants born with neural tube defects by the total number of live births in the country (1987–2012).A total of 1,170 newborns with neural tube defects were identified from 1987 to 2012 (1992–1995 data excluded); 628 were identified during the baseline pre-fortification period (1987–1991; 1996–1998); 191 during the fortification period (1999–2002); and 351 during the post-fortification time period (2003–2012). The overall prevalence of neural tube defects decreased from 9.8 per 10,000 live-births (95 % CI 9.1–10.5) for the pre-fortification period to 4.8 per 10,000 live births (95 % CI 4.3–5.3) for the post–fortification period. Results indicate a statistically significant (P < 0.05) decrease of 51 % in the prevalence of neural tube defects from the pre-fortification period to the post-fortification period. Folic acid fortification via several basic food sources has shown to be a successful public health intervention for Costa Rica. Costa Rica’s experience can serve as an example for other countries seeking to develop and strengthen both their birth defects surveillance and fortification programs.

Recibido el 9/Noviembre/2001. Aceptado para publicación el 12/Julio/2002. Este artículo está disponible en http://www.uady.mx/~biomedic/rb031413.pdf Artículo Original Rev Biomed 2003; 14:5-10. Artemisa medigraphic en línea 6 Revista Biomédica P Salas-Chaves, S Rodríguez-Aguilar, L Cunningham-Lucas, I Castro-Volio. SUMMARY.Utility of the alpha-fetoprotein in the prenatal diagnosis of neural tube defects and chromosomal abnormalities. Introduction. The present study focuses on the utility of AFP in prenatal diagnosis of 96 Costa Rican pregnant women. Material and methods. In these women, genetic amniocentesis and AFP levels were done between the 15 th and 25 th week of gestation. There were two main reasons for referral: abnormal ultrasound assessment and advanced maternal age. Results. The concentration values of AFP were expressed as multiples of the median, considering a value of 2.5 MoM as a normal superior limit and of 0.25 as the inferior limit. The confidence limits of the median were 562-1196 KU/l and the 2.5MoM value was located between 1404-2989 KU/l. Four cases had AFP levels higher than the median: one case of Turner Syndrome, another case of encephalocele and two normal karyotypes. Four other cases had AFP levels lower than 0.25 MoM: a case of trisomy 21, a case of trisomy 18, a case of omphalocele and a normal karyotype. Discussion. Prenatal diagnosis of fetal defects allowed genetic counseling as well as better obstetric management and pediatric care. (Rev Biomed 2003; 14:5-10)