Survival and reproduction among males with birth defects and risk of recurrence in their children.

CONTEXT: Few systematic data exist on survival and reproduction among males with birth defects and their contribution to occurrence of birth defects in the next generation.
OBJECTIVE: To estimate survival of males with registered birth defects, their subsequent reproduction rates, and their risk of transmitting birth defects to their offspring. DESIGN AND
SETTING: Population-based cohort study of data from the Medical Birth Registry of Norway.
SUBJECTS: A total of 486 207 males born in Norway between 1967 and 1982, 12 292 of whom had a recorded birth defect. MAIN OUTCOME MEASURES: Survival rates through 1992, reproduction rates through 1998, and risk of birth defects among offspring of males with vs without birth defects.
RESULTS: Survival through 1992 was lower among males with birth defects (84% vs 97%). Compared with males without birth defects, affected males were 28% less likely to have had a child. Among offspring of affected males, 5.1% had a registered birth defect compared with 2.1% of offspring of males without birth defects (relative risk [RR], 2.4; 95% confidence interval [CI], 1.9-3.0). Offspring of affected fathers had an increased risk of the same defect as their fathers (RR, 6.5; 95% CI, 4.0-10.4) and an increased risk of dissimilar defects (RR, 1.8; 95% CI, 1.3-2.5).
CONCLUSIONS: Compared with unaffected males, males with birth defects have higher mortality and survivors are less likely to have a child. Fathers with birth defects are significantly more likely than unaffected fathers to have an affected child.