The American Veterinary Medical Association says a recent study suggests that pregnant veterinarians have a higher risk for preterm delivery if they work long hours or perform surgery in the absence of a system for scavenging waste anesthetic gases. Another study indicates that occupational exposure to radiation or pesticides may increase the risk of birth defects.

The studies appeared in the May issues of the journal Obstetrics and Gynecology and the Journal of Occupational and Environmental Medicine, respectively. They are part of a series of studies analyzing data from a survey of veterinarians who graduated from Australian schools between 1960 and 2000. Previous analysis of the data indicated that pregnant Australian veterinarians with occupational exposure to anesthetic gases, radiation, or pesticides may have twice the risk of miscarriage (see JAVMA, May 15, 2008, page 1445).

The study of preterm delivery found that the prevalence was 7.3% in pregnant veterinarians who had exposure to anesthetic gases, in comparison with 5.7% in the general population. Further analysis revealed a dose-response relationship. The risk of preterm delivery also was higher for pregnant veterinarians who worked more than 45 hours per week, in comparison with those who worked fewer hours.

The other study found an increase in the risk of birth defects among the children of female veterinarians who took more than 10 radiographs per week while pregnant. The risk of birth defects was also increased after occupational exposure to pesticides at least once a week in veterinarians working exclusively in small animal practice