This section evaluates the findings on birth defects in the offspring of veterans, adverse pregnancy outcomes, infertility, and sexual problems. As appropriate, the major results from each study are addressed by whether the father or the mother served in the gulf and by outcome. Table 4-14 summarizes all the primary studies on adverse reproductive and perinatal outcomes reviewed by the committee.
Birth defects occur in about 3% of live births. The numerous types of serious or disabling birth defects include structural defects, chromosomal abnormalities, and birth defect syndromes (California Birth Defects Monitoring Program, 2009). Because of that diversity, epidemiologists attempting to calculate whether birth defects are increased in a particular group such as deployed veterans, sometimes encounter the problem of making multiple comparisons; that is, the greater the number or the more types of comparisons, the greater the likelihood that one or more of them will appear significant when no true differences exists. Several statistical techniques are used to adjust for, or minimize, the problem of multiple comparisons, but they are not foolproof.
In the most comprehensive population-based study, Araneta et al. (2003) identified birth defects among infants of military personnel born from January 1, 1989, to December 31, 1993, from population-based birth defect registries in six states: Arizona, Hawaii, Iowa, and selected counties of Arkansas, California, and Georgia (metropolitan Atlanta). They compared the prevalence of 48 selected congenital anomalies diagnosed from birth to the age of 1 year between Gulf War veterans’ and nondeployed veterans’ infants conceived before the war; between Gulf War veterans’ and nondeployed veterans’ infants conceived during or after the war; and between infants conceived by Gulf War veterans before and after the war. The authors performed separate analyses on the basis of whether the mother or the father was engaged in military service. If both parents were in the military then the birth was categorized as an infant of a military mother. The study found higher prevalence of three cardiac defects (tricuspid valve insufficiency, aortic valve stenosis, and coarctation of the aorta), and one kidney defect (renal agenesis and hypoplasia) among infants conceived after the war to Gulf War veteran fathers. There also was a higher prevalence of hypospadias (malformation of the urethra and urethral groove), a genitourinary defect among sons conceived postwar to Gulf War veteran mothers compared to their nondeployed counterparts. Aortic valve stenosis, coarctation of aorta, and renal angenesis and hypoplasia were also elevated among infants conceived among the Gulf War veteran fathers postwar compared to those conceived prewar. There was only 1 birth defect recorded among 142 births conceived prewar to Gulf War veteran mothers, and this precludes comparisons with this group.
This study is particularly informative because it relies on active surveillance systems to identify medically confirmed outcomes diagnosed through the first year, rather than at birth, and uses information from population registries, as opposed to information from voluntary participation by study subjects. Because both nonmilitary and military hospitals participated in