Paternal and maternal exposure to welding fumes and metal dusts or fumes and adverse pregnancy outcomes

OBJECTIVE: We assessed whether paternal exposure prior to conception and maternal exposure during pregnancy to welding fumes (WF) and metal dusts or fumes (MD/F) independently and jointly increases the risk of preterm delivery, low birth weight, and small-for-gestational age. METHODS: The study population was selected from The Finnish Prenatal Environment and Health Study of 2,568 newborns (response rate 94%) and included 1,670 women who worked during pregnancy of which 68 were exposed either to WF and/or MD/F. RESULTS: The risk of SGA was related to maternal exposure to WF only (adjusted OR = 1.78; 95% CI 0.53-5.99), MD/F only (adjusted OR = 1.77; 95% CI 0.38-8.35) and both exposures (2.92; 1.26-6.78). The corresponding effect estimates for preterm delivery were 2.66 (0.32-22.08), 5.64 (1.14-27.81) and for birth weight below 3,000 g 3.79 (1.09-13.19), 1.85 (0.56-6.14) and 1.70 (0.70-4.15), respectively. There was some suggestive, inconsistent evidence that the risk of preterm delivery and SGA is related to paternal exposure to WF. CONCLUSIONS: The present results provide evidence that maternal exposure to WF or MD/F combination during pregnancy may reduce fetal growth and suggestive evidence that paternal exposure to WF may increase the risk of preterm delivery and small-for-gestational age. The small number of exposed women and the lack of data for exposure concentrations suggest the need for further study to verify our findings.