Birth defect risk doubles in first-cousin marriages

The Born in Bradford study, which followed the health of 13,500 babies born at Bradford Royal Infirmary between 2007 and 2011, has found that marriage between first cousins doubles the risk of children being born with birth defects.

The researchers, investigating the higher than expected rates of deaths and congenital abnormalities seen among babies in the Pakistani community, concluded that the cultural practice of marriage between first cousins was a bigger factor than any other, outweighing deprivation in parts of the city and accounting for 31% of all birth defects.

The risk of having a baby with birth defects, usually heart or nervous system problems, is still small but rises from 3% in the general Pakistani population to 6% among those married to blood relatives.

Dr Eamonn Sheridan, lead author of the study, said the issue is ‘incredibly sensitive’ but he praised the community engagement in the research.