[Congenital malformations in Sweden].

The thalidomide catastrophy in the early 1960th clearly demonstrated the need of accurate epidemiological data of birth defects. Since 1963 there is in Sweden like in many other countries a continuous registration of congenital malformations in order to provide data for the early detection of changes in frequencies or patterns of defects and thus also to facilitate early identification of new environmental teratogens. During the more than 20 years period the Swedish register has been in operation an increase in the incidence of certain malformations such as omphalocele, hypospadia and Down's syndrome in the offspring of young mothers has been observed. Despite rather extensive studies no explanation for these changes has so far been found. Due to the great concern in the public about the relation between environmental factors and the occurrence of congenital malformations it is of great importance that the register can be used to elucidate the situation when there has been a suspicion of increased teratogenic risks in certain areas of Sweden or when pregnant women have special working conditions. The rate of malformations has been found to be higher among infants born to women coded as laboratory technicians than in the rest of the Swedish population. So far, no specific teratogenic factor has been identified. In Sweden no relation has been found between the incidence of congenital malformations and socioeconomic conditions. The incidence of neural tube defects has been found to be higher than expected in a count in Western Sweden.(ABSTRACT TRUNCATED AT 250 WORDS)