Marriage: Relatives
(asked on 19th January 2026) - View Source
Question to the Department of Health and Social Care:
To ask the Secretary of State for Health and Social Care, pursuant to the Answer of 12 January 2026 to Questions 89643, what health risks his Department has identified in relation to first cousin marriage; and whether the Department intends to publish the (a) evidence and (b) analysis informing those assessments.
The National Disease Registration Service is working with hospital trusts to continually improve the quality and completeness of data.
The Born in Bradford study provides the most definitive United Kingdom based evidence of risk of congenital anomalies. Results of this are publicly available at the following link:
https://borninbradford.nhs.uk/our-impacts/findings/?sf_paged=2
This includes a summary of health risks associated with consanguinity, specifically in Born in Bradford Evidence Briefing on Genes and health: Inheritance and Risk, available at the following link:
The Born in Bradford data indicated the risk of genetic abnormalities doubles, from 3% to 6%, in infants where parents are first cousins, similar to the increase in risk for mothers of white British origin older than 34 years old. Further information on this is available at the following link:
https://pubmed.ncbi.nlm.nih.gov/23830354/
Other publicly available academic research also indicates that miscarriage, stillbirth, and neonatal mortality are higher among consanguineous couples than non-consanguineous couples, with further information available at the following two links: