Birth defects surveillance. A pilot system in the Cape Peninsula

A pilot birth defects surveillance system was established in 1982 as part of an epidemiological baseline study pertaining to potential changes in water quality in the Cape Peninsula. The methodology used for reporting birth defects for two information systems, one hospital-based and the other population-based, utilizing statutory notifications of births, is described. Preliminary birth defect rates by cause are presented for a hospital-based system and are consistent with rates reported internationally. The system based on statutory notifications showed gross under-reporting.