High prevalence of down syndrome in the Rancagua Hospital in central Chile Alta prevalencia de síndrome de down en el Hospital Regional Rancagua, Chile. Período 1997-2003

Abstract

Background: The Latin American Collaborative Study for Congenital Malformations (ECLAMC) has detected a higher incidence of Down syndrome in a zone of central Chile than in the rest of the country. Aim: To analyze the incidence rates of Down syndrome between 1997 and 2003 at the Regional Hospital of Rancagua, located 90 km south of Santiago, Chile. Material and methods: The information obtained by ECLAMC was used. This program, using a case control methodology, registers all newborns with congenital malformations and assigns, as a control, the next normal newborn of the same sex. Results: During the study period, 106 newborns with Down syndrome were registered, with a mean rate of 29.61 per 10,000 live births, twice higher than expected. The rate variations along the years of study suggest a cyclic change, with a hemicycle of six years. Conclusions: In this hospital, mothers under 35 years of age, have twice the risk of having a child with Down syndrome, than in the rest of the country