How safe is a consanguineous marriage?

Q: I am involved with a girl who is the cousin sister of my father she is 2 years younger to me (my fathers uncle's daughter). We are planning to get married, but our families are opposed for this. Such type of practice has never been done in our family before. Can we face any problems in future regarding sex and child birth? Both of us don't have any hereditary disease.

A:In a consanguineous marriage, the risk of abnormality in the offspring increases to about 1.5 times the level in the non-consanguineous. In usual marriage (not between relatives) the risk of abnormality is about 3%, in consanguineous marriage of the type you are planning this increases to 4.5-5%. There is still 95% chance of having a normal baby. For more details, and the tests which may be done during pregnancy to detect any abnormality you should consult a geneticist.