No evidence for congenital malformations or prenatal death in infants bornto women with a high dietary intake of fish contaminated with persistent organochlorines

Objectives: The aim of the present study was to assess whether a high dieta ry intake of fatty fish from the Baltic Sea, contaminated with persistent o rganochlorine compounds, might increase the risk for congenital malformatio ns and perinatal death. Methods: A cohort of fishermen's wives from the Swe dish east coast (at the Baltic Sea) were linked to the Swedish Medical Birt h Register (MBR), resulting in the identification of 1501 infants born in t he period 1973-1991. A further linkage with the Swedish Registry of Congeni tal Malformations was performed. Similar linkages were made for a compariso n group of fishermen's wives from the Swedish west coast, who gave birth to 3553 infants during the study period. The reproductive end points studied included congenital malformations, stillbirths, and early neonatal deaths. The expected numbers of these end points were calculated from the MBR data for the regional populations. Results: In the east coast cohort, 3.3% of th e infants had some malformation diagnosis as compared with 5.0% of the west coast cohort. As compared with the general population, somewhat fewer malf ormations than expected were diagnosed in the east coast cohort (risk ratio 0.78, 95% CI 0.58-1.04). No specific malformation was overrepresented in t he east coast cohort. The risk ratios for stillbirths and early neonatal de aths did not significantly differ from unity in any of the cohorts. Conclus ions: The present results exclude in an unequivocal way an association betw een exposure to persistent organochlorines from fatty Baltic Sea fish and a n increased risk for all congenital malformations and perinatal death. The limited power of the study design, however, does not allow the exclusion of slight risk excesses for some specific types of malformation.