More than 95% of all of the individuals with Hemophilia are males. In fact, about one out of every 5,000 males is born with Hemophilia. In about one-third of these cases, there is no known family history of the disorde

Hemophilia A and B are both inherited sex-linked disorders that are generally passed on from mother to son: A woman who has the gene for hemophilia, is called a carrier, and has a 50% chance of passing the gene on to each child she has. If she bares a child with the gene for hemophilia and the child is a female, she will also be a carrier. However, if her child is a male and inherits the gene, he will have Hemophilia. Various tests are available to determine if a woman is a carrier. Prenatal tests are also available to determine the Hemophilia status of the baby.

All female children of a man who has Hemophilia will be carriers. If he fathers a child with a carrier of the same disorder, there is a possibility that their female children will be born with the condition. In order for a male with hemophilia to father a male child with hemophilia, the gene would have to come from the mother as well. Some bleeding disorders, like von Willebrand’s, are not sex-linked; occurring with equal frequency in men and women.