Would Coumadin Affects Baby During Pregnancy?

Hello, My husband has been on coumadin for 3 years and we want to have a baby soon. His doctor said that he should not conceive while on coumadin because it will cause birth defects. I looked online and all I see is that if the mother takes it, there will be problems for the baby. Can men conceive a healthy, normal child while on coumadin? Sincerest Thanks, Kris