Boys born to a father with hemophilia and a mother who is not a carrier will not have the disease. This is because boys get the X chromosome from their mother and Y chromosome from their father. However, all daughters born to men with hemophilia will inherit the father's hemophilia gene. This is because they get one X chromosome from their mother and one X chromosome from their father. They thus will be carriers.
Some female carriers have no health problems or symptoms related to carrying the hemophilia gene.
These women are known as asymptomatic carriers. However, other female carriers have low factor levels that are associated with bleeding problems. These symptomatic carriers may suffer excessive menstrual bleeding, bruising, nosebleeds, and bleeding after surgery, dental work, or childbirth. Stress, exercise, medicines, and changing hormone levels during menstruation and during and after pregnancy all may affect the bleeding patterns of symptomatic carriers. Female carriers who have excessive bleeding should be evaluated by a doctor skilled in treating bleeding disorders.