Objectives: Several adverse pregnancy outcomes were reported among female laboratory workers in a North American aluminum smelter. To determine whether these outcomes were associated with any occupational exposure at the plant, a cross-sectional survey was undertaken.
Methods: Rates of miscarriage, premature singleton birth, and major congenital anomaly occurring during employment were compared with a reference group comprised of all pregnancies that occurred before employment.
Results: Among female workers, the excess of congenital anomalies among female laboratory workers that defined the initial cluster was observed, but no specific pattern was found.
Conclusions: On the basis of these analyses, the increase in congenital anomalies could not be attributed to occupational exposures at the smelter nor could potential exposure likely explain the diverse anomalies described.