Description and mission evaluation of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996

Background: The Hungarian Case-Control Surveillance of Congenital Abnormali ties was established in 1980, This article describes how the Hungarian Case -Control Surveillance of Congenital Abnormalities was first organized and i s currently maintained. The baseline statistics are provided and potential venues of postmarketing surveillance of drug teratogenicity and other publi c health tasks and research are proposed. Methods: Cases with congenital abnormalities and patient controls with Down syndrome were selected from the Hungarian Congenital Abnormality Registry. Population controls without congenital abnormalities were selected from th e National Birth Registry on the basis of three matching criteria: sex, wee k of birth, and district of parent's residence. Three sources of informatio n concerning drug exposures, maternal disorders, and pregnancy complication s, among others, were used: (1) prospective and medically recorded data fro m antenatal care logbooks and discharge summaries; (2) retrospective matern al self-reported data obtained with a structured questionnaire in all the t hree study groups; and (3) data collected by regional nurse in house visits to nonrespondent cases and patient controls. Twenty-five congenital abnorm ality groups were evaluated. During the 17-year period of data collection, 22,843 cases, 38,151 population controls, and 834 patient controls were inc orporated into the data set, constituting the largest population-based case control data set of congenital abnormalities to date. Results: Demographic features of pregnant women and informative offspring a re presented along with the distribution of 25 main groups of congenital ab normalities. Conclusions: This system is appropriate for postmarketing the surveillance of drug teratogenicity, for the improvement of congenital abnormality diagn osis, to get informed consent, to have a communication with parents and to provide material for research. Teratology 63.176-185, 2001. (C) 2001 Wiley- Liss, Inc.