What is the typical recurrence risk of congenital heart disease (CHD) in siblings according to existing medical knowledge?

The recurrence risk of congenital heart disease (CHD) in siblings is generally understood to be in the range of 3-4%. This estimation is grounded in various epidemiological studies that have examined the familial aggregation of CHD and identified factors influencing the likelihood that siblings of an affected child will also be born with some form of cardiac anomaly.

Several factors contribute to this recurrence risk, including genetic predispositions, environmental influences, and underlying conditions like maternal diabetes or certain teratogenic exposures. While the overall prevalence of CHD is about 1 in 100 live births, the increased risk for siblings of affected individuals reflects a combination of both genetic factors and the broader hereditary patterns associated with these congenital malformations.

As for the other options, the lower values do not adequately capture the enhanced risk seen in siblings of affected children, while the higher values may overestimate the recurrence risk based on current data. Thus, the 3-4% range provides a more accurate representation of the typical recurrence risk for siblings in the context of congenital heart disease.