(95% CI 0.92-1.15) for male active-duty veterans, 0.92 (95% CI 0.71-1.20) for female active-duty veterans, and 1.00 (95% CI 0.90-1.10) for men and women combined. The authors note that when the adjusted ORs were calculated, no associations were seen, but they did not provide the data. When birth defects were evaluated by ICD-9-CM diagnostic groupings for the five most common severe anomalies, no statistical increases in associations were observed for male or female veterans. A limitation of the study is that it examined data only from live births to active-duty personnel in military hospitals. It is likely that higher risk pregnancies were referred to civilian hospitals. Since not all congenital malformations are evident at birth, some outcomes may have been underascertained when relying on hospital birth records.
A population-based study of male Canadian veterans (Goss Gilroy, 1998) surveyed deployed and nondeployed veterans for self-reported birth defects. Overall, deployed veterans reported a higher prevalence of birth defects (a combined category that included births before, during, and after the Gulf War). Birth defects that occurred at similar frequencies included urogenital and kidney defects.
Two additional secondary studies assessed broad groups of birth defects. In a population-based survey in the United States, Kang et al. (2001) observed an excess prevalence of self-reported “likely birth defects” and specifically “moderate to severe defects” among infants of Gulf War deployed fathers and mothers compared with nondeployed fathers and mothers. Most defects were isolated anomalies, and no clear patterns were found. First pregnancies ending after June 30, 1991, were considered in this analysis. The observed number of birth defects among children (liveborn and stillborn) born after deployment to National Guard personnel in two units in southeast Mississippi was not greater than expected on the basis of population-based registries (Penman et al., 1996).
Doyle et al. (2004) was considered secondary in Volume 4, but it is considered primary in this review, primarily due to medical confirmation of self-reported outcomes. Doyle and colleagues (2004) evaluated the prevalence of self-reported birth defects among the offspring of all UK veterans (male and female) deployed to the gulf and among the offspring of nondeployed veterans who responded to a postal questionnaire. Response rates were higher among the Gulf War veterans (53% of men, 72% of women) than the comparison group (42% of men, 60% of women). The authors considered pregnancies conceived after deployment (after January 1, 1991, for nondeployed veterans) through November 8, 1997. Medical confirmation was requested for all fetal deaths at 16 weeks or more or of unknown gestation and for liveborn children in whom a congenital abnormality, serious childhood medical condition, or death was reported. Among infants conceived by fathers deployed to the gulf compared with infants of fathers not deployed, the OR for any malformation was 1.5 (95% CI 1.3-1.7). Elevated ORs were observed specifically for malformations of the genital system, urinary system, musculoskeletal system, and cranial neural crest; for “other” malformations of the digestive system; for “other” nonchromosomal malformations; and for metabolic and single-gene defects. The ORs for urinary system and musculoskeletal system defects remained increased when the cases were restricted to the 55% that had clinical confirmation. No significant associations with birth defects were found for infants of mothers deployed to the gulf, although the analyses were limited by small numbers.