Occupational exposure to inhaled anesthetic. Is it a concern for pregnant women?

Two of my pregnant patients are exposed to inhaled anesthetic on the job. One is an anesthetist, and the other is a veterinarian. They have both expressed concern about this exposure. How should I advise them?

Occupational exposure to waste anesthetic gas is not associated with increased risk of major malformations. Risk of spontaneous abortion might be slightly increased, however. This risk can be reduced, if not eliminated, by good gas scavenging systems.