Paternal military service in Vietnam and the risk of late adverse pregnancy outcomes.

To investigate the relationship between paternal military service in Vietnam and the risk of late adverse pregnancy outcomes, we conducted a case-control study of women who delivered infants from August 1977 until March 1980 at Boston Hospital for Women. Paternal military service history among 857 congenital anomaly cases, 61 stillbirth cases, and 48 neonatal death cases were compared with that of 998 normal controls. Military service veterans were identified by crossmatching identifying information from obstetric records with state and national military records. After controlling for confounding variables, we found that the Vietnam veterans' relative risk of fathering an infant with one or more major malformations was 1.7 (95% CI = 0.8, 3.5) compared to non-Vietnam veterans. The increased risk was present in several organ systems and did not seem to be related to a particular type of defect. No associations or highly unstable associations were found between paternal military service in Vietnam and the occurrence of congenital anomalies overall, minor malformations, normal variants, stillbirths, and neonatal deaths. These findings should be viewed with caution since maternal and delivery characteristics appear to have contributed to the etiology of several of the major malformations among the Vietnam veterans' children.