In short, yes, it is legal for second and third cousins to marry in the US. The risk of birth defects in children born to first cousins is increased from a baseline of 3-4 percent to 4-7 percent, according to the National Society of Genetic Counselors.

Is it legal to marry your 3rd cousin UK?

Its legal to marry your cousin in the UK - and it happens more often than you might think. Marriage between cousins is a contentious topic across the globe, but you may be surprised to hear its completely legal in the UK.