Carrying the haemophilia gene

Carrying the haemophilia gene

Last reviewed: October 2011

Many girls or women who carry the gene causing haemophilia do not have symptoms of a bleeding disorder. If at least one of their X chromosomes has a factor VIII or IX gene that works, their body can usually produce normal or near normal levels of factor and they do not have bleeding problems.

However, some girls and women who carry the haemophilia gene may have a bleeding tendency. Females who have bleeding related to haemophilia are often described as “symptomatic carriers”. If their factor levels fall in the range for mild haemophilia (5 – 40% of normal clotting factor), they may sometimes also be referred to as having “mild haemophilia”.

Examples of having a bleeding tendency or symptoms may include:
• Bruising easily
• Having heavy menstrual bleeding
• Having excessive bleeding after dental surgery or extractions, other surgery or accidents
• Have prolonged bleeding after childbirth.


All females who carry the haemophilia gene should have testing for their clotting factor levels periodically, as their factor levels may change with age, pregnancy and hormonal medications. If their factor level is low, they will need a treatment plan to manage situations if they occur or prevent them.

Managing symptoms

Genetic testing

Pregnancy and childbirth

Tips for women who carry the haemophilia gene

References and reviewers

Important Note: This information was developed by Haemophilia Foundation Australia for education and information purposes only and does not replace advice from a treating health professional. Always see your health care provider for assessment and advice about your individual health before taking action or relying on published information.

This information may be printed or photocopied for educational purposes.

Last Updated: 5th Nov 12