Consanguineous marriage and its relevance to obstetric practice.

At the beginning of the twenty-first century, consanguineous marriage is practiced widely in many parts of the world. More than 2 billion people, of various religious and ethnic backgrounds, live in countries where a large proportion of marriages are contracted between blood relatives. The practice is seen as promoting family stability and having significant social and economic advantages. Consanguineous marriage is important genetically-the children of consanguineous unions are more often homozygous for particular alleles than are the offspring of unrelated parents, and therefore, autosomal recessive disorders, which may be lethal or debilitating, are more common in such children. Health-care providers working with communities where consanguineous marriage is common, in particular obstetricians, family physicians, and pediatricians, need to be aware of the possible impact of such marriages on pregnancy outcomes, so the best possible genetic and antenatal care can be provided, sympathetically and nonjudgmentally, and the best possible results obtained.