PATERNAL SERUM DIOXIN AND REPRODUCTIVE OUTCOMES AMONG VETERANS OF OPERATION RANCH HAND

We studied whether paternal exposure to Agent Orange and its dioxin co ntaminant (2,3,7,8 tetrachlorodibenzo-p-dioxin) during the Vietnam War is related to adverse reproductive outcomes after service in Southeas t Asia. The index cohort comprises conceptions and children of veteran s of Operation Ranch Hand, the unit responsible for aerial spraying of herbicides in Vietnam from 1962 to 1971. The comparison cohort compri ses conceptions and children of Air Force veterans who served in South east Asia during the same period but who were not involved with sprayi ng herbicides. We found no meaningful elevation in risk for spontaneou s abortion or stillbirth. In analyses of birth defects, we found eleva tions in risk in some organ system categories, which, after review of the clinical descriptions, were found to be not biologically meaningfu l. There was an increase in nervous system defects in Ranch Hand child ren with increased paternal dioxin, but it was based on sparse data. W e found no indication of increased birth defect severity, delays in de velopment, or hyperkinetic syndrome with paternal dioxin. These data p rovide little or no support for the theory that paternal exposure to A gent Orange and its dioxin contaminant is associated with adverse repr oductive outcomes.