I was very scared when I found out I was pregnant with my first cousins baby. I was so afraid I would give birth to a baby who had defects. After discussing with my Dr. about why I was concerned about the pregnancy, he told me, I could have a normal & healthy baby like any other woman. He did the normal tests that you get done while being pregnant and everything was fine in my case. I gave birth to a very healthy 8lb 3.5 oz baby boy. To this day, we have a normal, healthy 40 year old. :-) I would suggest you talk with your Dr. first and see what he/she thinks. I am quite sure blood tests can provide the information needed so, you can decide what course of action you and your cousin should take with having a child. Wishing you all the best.