Midwives have been told about the benefits of “close relative marriage” in training documents that minimise the risks to couples’ children.
The documents claim “85 to 90 per cent of cousin couples do not have affected children” and warn staff that “close relative marriage is often stigmatised in England”, adding claims that “the associated genetic risks have been exaggerated”.
Why did you bring birth defects up if marriage is the concern? You don’t get birth defects from a wedding.
Also in basically every state where it’s illegal to marry your cousin it’s illegal to have sex with them, too.
(When I say basically I mean I’m too tired to check half of the US’s laws on this, and the source I’m using says sexual contact is generally not permitted)