A prospective-controlled study of pregnant veterinary staff exposed to inhaled anesthetics and x-rays.

Most veterinary staff are women of reproductive age. They are exposed to "waste" anesthetic gas and ionizing radiation in their workplace, which may endanger fetal safety. Presently, exposure of female veterinary staff to these health hazards has not been adequately addressed in the medical literature. Our primary objective was to investigate the incidence of major malformations associated with occupational exposure to inhaled anesthetics and/or radiation among pregnant veterinary staff. The secondary objective was to determine the rates of other adverse outcomes. We prospectively collected data on and followed-up women occupationally exposed to inhaled anesthetics and/or radiation in veterinary practices in Ontario, and compared them to controls matched for maternal age and gestational age at the time of call to the Motherisk Program. A total of 95 women were prospectively enrolled and followed-up. Among the participants there were 87 (93.5%) and 88 (92.8%) livebirths in the study and control groups, respectively. There were 4 (4.8%) major birth defects in the study group and 3 (3.4%) in the control group. The rates of spontaneous abortion were also similar, 6 (6.4%) cases in the study group and 7 (7.4%) cases in the control group. These results suggest that Ontario female veterinary staff exposed to inhaled anesthetics and/or radiation do not seem to be at an increased risk for major malformations above baseline risk.