Fetal death and congenital malformation in babies born to nuclear industryemployees: report from the nuclear industry family study

Background There is some concern about the genetic effects of exposure to l ow-level ionising radiation, but the evidence is sparse and conflicting. Mo st work has concentrated on cancer in offspring and little has been done on adverse reproductive outcome. We aimed to assess whether the offspring of men and women who are occupationally exposed to ionising radiation are at i ncreased risk of fetal death and congenital malformation. Methods We analysed pregnancies reported by an occupational cohort of nucle ar industry workers in the UK, employed at establishments operated by the A tomic Energy Authority, Atomic Weapons Establishment, and British Nuclear F uels. Employment and radiation monitoring data supplied by employers was li nked to each pregnancy. Findings 11 697 men and 1903 women reported one or more singleton pregnancy conceived after first employment within the nuclear industry, the men repo rting a total of 23 676 singleton pregnancies and the women 3585. The risks of fetal death and congenital malformation were not related to whether the father had been monitored before conception or to the dose of radiation re ceived. Among pregnancies reported by women, the risk of early (<13 weeks o f gestation) miscarriage was higher if the mother had been monitored before conception (odds ratio [OR] 1.3, 95% CI 1.0-1.6), but there was no trend w ith dose, The risk of stillbirth was also higher if the mother had been mon itored before conception (OR 2.2, 95% CI 1.0-4.6), but the finding was base d on only 29 cases (13 exposed). The risk of any major malformation, or of specific groups of malformations, was not associated with maternal monitori ng, or dose received, before conception. Interpretation We found no evidence of a link between exposure to low-level ionising radiation before conception and increased risk of adverse reprodu ctive outcome in men working in the nuclear industry. Similarly for women t here was no evidence of an association between monitoring before conception and malformation in offspring, The findings relating maternal preconceptua l monitoring to increased risk of fetal death are equivocal and require fur ther investigation.