Planning to marry a first cousin? According to new research, you may be at a higher risk of having a baby with a birth defects.
Researchers have identified two factors that increase the risks of having a baby with birth defects - delayed motherhood and couples who are blood relatives.
The study published in The Lancet, found that couples who were first cousins (consanguine) were at double risks of having a baby with a birth defects like Down's syndrome, heart or lung defects etc.
Scientists from the University of Bradford and the University of Leeds looked at data of nearly 11,400 babies born in the U.K. between 2007 and 2011. The study proved the link between first cousin marriage and birth defects. It included 2,013 babies of first cousin parents, belonging to different ethnic groups- mainly of Pakistani origin (1,922) and the rest British.
According to the background information provided in the study, birth defects are more common among Pakistani babies and it claims the lives of a significant number of Pakistani children under the age 12.
Lead author, Eamonn Sheridan from the University of Leeds analyzed the prevalence of birth defects among the participants through medical records, questionnaire data. Factors that have long been associated with increasing risks of birth defects, including maternal lifestyle, smoking habit, deficits and obesity were also taken into consideration.
Of the total children part of the Born in Bradford (BiB) study, 386 were born with a defect. Researchers found that birth defects were alarmingly high among the Bradford babies (305.74 per 10,000 live births) compared to the national rate (165.90 per 10,000).
They also found consanguinity contributing to 31 percent of the total birth defects in Pakistani children. Apart from that, the study also found children born to older women at similar risks of birth defects.
"Consanguinity was associated with a doubling of risk for congenital anomaly," the authors, wrote while concluding their study, adding that, "31% of all anomalies in children of Pakistani origin could be attributed to consanguinity. We noted a similar increase in risk for mothers of white British origin older than 34 years."