Birth Defects in Offspring of Female Veterinarians Adeleh Shirangi, MPH, PhD Lin Fritschi, MBBS, PhD C. D’Arcy J. Holman, MBBS, MPH, PhD Carol Bower, MBBS, PhD Learning Objectives • Demonstrate familiarity with current knowledge on the risk of birth defects associated with radiation and other exposures among health care workers, as well as female veterinarians. • Characterize the excess risk of birth defects in female veterinarians, along with the relevant risk factors. • Present advice regarding reproductive health and measures to reduce the risk of birth defects for female veterinarians, including areas of uncertainty where further research is needed. Abstract Objectives: To investigate the risk of birth defects in offspring of female veterinarians exposed to occupational hazards such as radiation, anesthetic gases, and pesticides in veterinary practice. Methods: The Health Risks of Australian Veterinarians project was conducted as a questionnaire-based survey of all graduates from Australian veterinary schools during the 40-year period 1960 –2000. Results: In a multiple logistic regression controlling for the potential confounders, the study showed an increased risk of birth defects in offspring of female veterinarians after occupational exposure to high dose of radiation (taking more than 10 x-ray films per week, odds ratio: 5.73 95% CI: 1.27 to 25.80) and an increase risk of birth defects after occupational exposure to pesticides at least once per week (odds ratio: 2.39 95% CI: 0.99 to 5.77) in veterinarians exclusively working in small animal practice. Conclusion: Female veterinarians should be informed of the possible reproductive effects of occupational exposures to radiation and pesticides. (J Occup Environ Med. 2009;51:525–533) T he World Health Organization has estimated that 3% to 6% of all live born infants will have congenital anomalies, which include neural tube defects, cardiovascular system mal- formations, and oral-facial clefts. 1 The frequency depends on the time of observation after birth, the defini- tion and types of malformations in- cluded, geographic variation and the differences in reporting and statisti- cal procedures. Occupational and environmental agents are suspected causes of at least some of the approximately 65% of birth defects for which etiology is un- known. 2 Some occupations in health care workers and occupational expo- sure to radiation have been suggested as being associated with increased risk of birth defects such as nursing occu- pations, 3 medical radiographers, 4 and other hospital personnel. 5 Conversely, a study in female veter- inary staff and some studies in other occupations have not revealed any as- sociation between exposure to ionizing radiation and malformations. 6–8 A study in the US compared female veterinarians with lawyers and re- ported a higher rate of reportable birth defects among the veterinarians than among the lawyers (relative risks [RR]: 4.2; 95% CI: 1.2 to 15.1), although this study was not designed to detect an increase in birth defects. 9 Most of the existing evidence in humans indicates no associations be- tween occupational exposures to in- haled anesthetic gases and increased risk of congenital birth defects. 6,8,10 There has been no evidence of sig- nificant association between expo- sure to pesticides in health care workers and increased risk of birth defects, although maternal involve- ment in agricultural activities and From the School of Population Health (Dr Shirangi, Dr Holman), Faculty of Medicine, Dentistry and Health Sciences, The University of Western Australia, Crawley, Australia; Western Australian Institute for Medical Research (Dr Fritschi), Sir Charles Gairdner Hospital, Nedlands, Australia; Division of Population Sciences (Dr Bower), Telethon Institute for Child Health Research, Centre for Child Health Research, The University of Western Australia and Western Australian Birth Defects Registry, King Edward Memorial Hospital, SUBIACO, Australia. Adeleh Shirangi and coauthors have no commercial interest related to this research. Address correspondence to: Adeleh Shirangi, Department of Epidemiology and Public Health, Imperial College London, St Mary’s Campus, Norfolk Place, London, W2 1PG; E-mail: a.shirangi@imperial.ac.uk. Copyright © 2009 by American College of Occupational and Environmental Medicine DOI: 10.1097/JOM.0b013e3181a01af3 CME Available for this Article at ACOEM.org JOEM • Volume 51, Number 5, May 2009 525