Hi, cystic fibrosis is a genetic disorder and if your brother suffered from it, there is a chance that you are a carrier of mutated gene that causes cystic fibrosis. If your husband has no family history of cystic fibrosis there is a great possibility that he is not a carrier of the mutated gene and that you will have a healthy offspring, because cystic fibrosis has been diagnosed only in children whose both parents are carriers. Because you are very concerned about this I would suggest that you and your husband get tested to see if you are carriers of the mutated gene. However, because mutation in the gene may pass undetected, I would also recommend that when you get pregnant you do an amniocentesis test, just to be sure. This test means that a doctor will use a syringe to take the amniotic fluid that has the same genes as your baby and do the required test.