Effect of occupational noise on the course and outcome of pregnancy

Abstract

OBJECTIVES - The goal of this investigation was to examine the effects of occupational noise during pregnancy prospectively. METHODS - The exposed group [continuous A-weighted sound level (L(Aeq(8h))) ≥78 dB] consisted of 111 pregnant women, and the reference group comprised 181 pregnant women with approximately similar work conditions but without noise exposure. The noise-exposed women had more frequently other inconveniences in their work, however, like shift work, impulse noise exposure, vibration, and a high or low temperature. RESULTS - With the limit of 78 dB (L(Aeq(8h))), the course and outcome of pregnancy did not differ between the groups. When the noise exposure was 90 dB (L(Aeq(8h))) or more, a decline in birthweight, either absolute [mean 3304 (SD 585) g for the exposed versus mean 3622 (SD 548) g for the unexposed, 95% CI of mean difference -471-+15 g] or related to the gestational age (below the 10th percentile [5 of 25 (20%) versus 13 of 180 (7%)]), was seen. These findings were more pronounced if the woman was simultaneously exposed to a standing work position or shift work. CONCLUSION - Working in high noise exposure can be considered a form of risk during pregnancy.