Birth defects and paternal occupational exposure. Hypotheses tested in a record linkage based dataset.
MAIN QUESTION: To test previously established hypotheses on associations of birth defects with paternal occupation on the basis of a Norwegian registry material.


METHODS
The study comprised all births in Norway 1970 -1993 for which linkage with population censuses 1970, -80 and -90 on parents' job title could be obtained--about 1 million births (75% all births). The reference population was offspring of the group that did not belong to the actual occupation.


RESULTS
Vehicle mechanics had an association with hypospadias--OR 5.19 (CI 1.31-14.24), painters had a non-significant association with spina bifida--OR 2.03 (CI 0.99-3.75) and printers with club foot--OR 1.61 (CI 0.89-2.90). Associations observed previously in off-spring of fathers in large occupational groups such as teachers, drivers, electricity related occupations, sales related occupations and agricultural workers were not confirmed in this dataset.


CONCLUSIONS
The study gave further evidence of cause effect relationships in the confirmed positive associations, though without any clarification of possible mechanisms involved. Possible false negative findings might be caused by low statistical power due to small occupational groups or non-differential misclassification of exposure.
Irgens
A
A
Department of Occupational Medicine, Haukeland University Hospital, Bergen, Norway.
Krüger
K
K
Skorve
A H
AH
Irgens
L M
LM
D000328:Adult; D000013:Congenital Abnormalities / Q000209:etiology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008498:Medical Record Linkage; D009664:Norway / Q000453:epidemiology; D016273:Occupational Exposure; D009790:Occupations; D018812:Paternal Exposure; D012042:Registries