Three additional studies were identified that evaluated the effect of deployment on birth defects (Ishoy et al., 2001a; Kelsall et al., 2007; Verret et al., 2008), although none met the criteria for primary studies. In addition to the criteria for secondary studies described above, studies were considered secondary if too few birth defect cases were identified to make meaningful comparisons. Thus, Araneta et al. (1997), which was previously described but not classified as either primary or secondary in Volume 4, is considered secondary in this review.
In a study of Goldenhar syndrome, DoD hospital discharge data were used to identify all infants born to active-duty personnel after the Gulf War (or December 31, 1990, for nondeployed veterans) through September 30, 1993 (Araneta et al., 1997). In the population of 75,414 infants, five cases born to Gulf War veteran fathers and two cases born to nondeployed fathers were identified (Araneta et al., 1997). Given the small numbers, it is difficult to determine whether an excess risk is associated with service in the gulf.
A study of Danish veterans assessed self-reported “congenital disease or malformations” for children born to male veterans after 1991 (Ishoy et al., 2001a). The prevalence of congenital malformations was 2.1% among the 661 peacekeepers and 2.8% among the 215 nondeployed veterans. The difference between the groups was not significant.
Kelsall et al. (2007) surveyed Australian Gulf War veterans (n = 1424) and nondeployed (n = 1548) Australian Defense Force personnel in 2000-2002 to compare self-reported birth defects and other reproductive outcomes. No association was observed between a father’s Gulf War deployment and any reported birth defect (OR 1.0, 95% CI 0.6-1.6). Evaluations of specific malformations were not reported. Birth defects data were collected for live births only, which would exclude the most severe malformations. Additional limitations include poor response among nondeployed veterans and lack of control for maternal factors.
When compared to 10-year prevalence data from the Paris Registry of Congenital Malformations, the prevalence of major anomalies did not differ between French Gulf War veterans and the general French population, with the exception of Down syndrome which occurred less frequently among veterans (prevalence ratio 0.36, 95% CI 0.13-0.78) (Verret et al., 2008). Within the same publication, the authors also report the results of a nested case-control study conducted within the cohort of French Gulf War veterans to assess the effects of Gulf War-related exposures on all birth defects combined. No associations were observed for self-reported exposures to the smoke of oil-well fires, sandstorms, chemical alarms, or pesticides. According to the authors, an effort was made to minimize recall bias by restricting controls to veterans with at least one symptom-related hospitalization. However, the inclusion criterion was not applied equally to the cases. Because control selection was plausibly related to exposure, the results of the case-control analyses were subject to selection bias.
Primarily on the basis of the Araneta et al. (2004) and Doyle et al. (2004) studies, because of the availability of medical confirmation in those studies, there is some suggestion of increased risk of birth defects among offspring of Gulf War veterans. However, with the possible exception of urinary tract abnormalities, the specific defects with increased prevalence in the two studies were not consistent. Furthermore, the association between deployment and urinary tract abnormalities was not consistent when considering parent-specific exposures. That is, the association observed in Araneta et al. (2004) was specific to maternal deployment, and the association observed in Doyle et al. (2004) was confined to paternal deployment. Overall, studies