Population surveillance of multimalformed infants--experience with the Swedish Registry of Congenital Malformations. First Part.

The paper discusses the principles of an analysis of infants with multiple malformations, recorded in a birth defect registry. It is illustrated with 973 multimalformed infants recorded in the Swedish Registry of Congenital Malformations, 1965-1984. The detection and delineation of patterns of associated malformations is described and exemplified with the VATER association pattern. There is no time trend for the rate of infants with this association; they represent about 4% of all registered multimalformed infants; and their prevalence at birth is 2.7 per 100,000 births. The rate of infants probably representing unidentified trisomy 13 shows a decrease after 1977 indicating an increased access to cytogenetic services. A similar decrease is seen in infants probably representing unidentified Meckel's syndrome. Using 28 multimalformed infants registered in 1985, the technique for surveillance of multimalformed infants in a population is discussed.