Haemophilia and carrying the gene

Can females have haemophilia?

Girls or women who have the gene alteration causing haemophilia can have normal or reduced factor VIII (8) or factor IX (9) levels. 

In genetics any female who has this gene alteration is called a 'haemophilia carrrier'.

Around 70% of females with the gene alteration have normal factor levels and do not have bleeding symptoms.

However, approximately 20-30% of girls and women who are carriers have reduced clotting factor levels. They often have bleeding symptoms and can have haemophilia.

In the past women and girls with bleeding symptoms were generally described as 'symptomatic carriers'.

Now if their factor levels fall in the range for haemophilia (less than 40% of normal clotting factor), they are diagnosed as having the medical condition haemophilia.

  • Usually they will have mild haemophilia (5 – 40% of normal clotting factor).
  • In very rare cases, some girls or women have particularly low factor levels causing them to have moderate or severe haemophilia.
  • Some females with factor levels at the lower end of normal (40-50%) may also experience abnormal bleeding. If further investigation shows that this bleeding is related to a factor VIII or IX deficiency, they will be treated as having haemophilia, but they will be described as a 'symptomatic haemophilia carrier'.

Factor level testing

All girls and women who are carriers should have testing for their clotting factor levels at least once, preferably as soon as a girl shows bleeding symptoms or before she starts menstruating.

If their factor levels are low, they will need a treatment plan to prevent bleeding problems and manage any situation that may occur, including medical and dental procedures and surgery.

Females with lower factor levels should have them checked periodically, as their factor levels may change with age, pregnancy and hormonal medications. 

Unlike males with haemophilia, where the factor level is nearly always the same within the same family, the factor level in females who are carriers is unpredictable and varies between family members.

It is important to remember that normal factor VIII or factor IX levels will not tell you whether you have the gene alteration causing haemophilia.

  • Many females who carry the gene alteration have normal factor levels.
  • Finding out your clotting factor level helps you and your Haemophilia Treatment Centre decide if you need to develop a treatment plan specifically for you.
  • If your levels are normal a separate genetic test is needed to find out if you have the gene alteration.

Click here for more information on genetic testing

See the HAEMOPHILIA TESTING IN WOMEN AND GIRLS section for detailed information

Or read the booklets:

Shorter/simpler version
Haemophilia testing in women and girls a guide
A guide to haemophilia testing in women and girls (genetic testing and factor level testing)

More comprehensive version

Haemophilia testing in women and girls
Haemophilia testing in women and girls: your questions answered (genetic testing and factor level testing)

Download the fact sheets:
Haemophilia A and haemophilia B
Haemophilia in females (PDF, 1.1 MB)

Working with your HTC
Haemophilia treatment and care for young women (PDF 1.3 MB) 

Date last reviewed: September 2023

What are the symptoms of haemophilia in females?

Examples of having a bleeding tendency or symptoms in females may include:

  • Bruising easily
  • Having more painful swelling and bruising than you would expect after an injury, eg falling off a bike, car accident, sporting injury
  • Heavy and/or long periods. This is called heavy menstrual bleeding or sometimes abnormal uterine bleeding or menorrhagia. It can lead to low iron levels or anaemia
  • Bleeding or oozing for a long time after dental surgery or extractions, other surgery and medical procedures, injuries or accidents
  • Heavy bleeding for extended time after childbirth (particularly with delayed or late postpartum haemorrhage)
  • Females with very low clotting factor levels may also have internal bleeding into joints, muscles, organs and soft tissues.

Heavy menstrual bleeding

Heavy periods or heavy menstrual bleeding can be difficult to define because what different girls and women call 'heavy' can vary. Doctors may also use the terms 'abnormal uterine bleeding' or 'menorrhagia'. These are some signs that menstrual bleeding is 'heavier' than average: 

  • Soaking through a tampon and pad around two hourly, or needing to change during the night
  • Periods that last longer than 8 days
  • Bleeding with clots bigger than a 50 cent piece in size.

Heavy menstrual bleeding can lead to anaemia (low red blood cell count/low blood iron levels), with symptoms of fatigue, paleness, lack of energy and shortness of breath.

Although these can be symptoms related to haemophilia, they can also be symptoms of a gynaecological disorder, so it is important to consult a gynaecologist.

With diagnosis and appropriate treatment, these bleeding problems can usually be reduced or managed.

Care and management

If you are a woman or girl with a bleeding disorder, a holistic or comprehensive care approach to your health care can help you to achieve better health and quality of life. Specialist gynaecological care over your lifetime is important to manage any gynaecological issues that occur. These may not be related to haemophilia, but in some cases the bleeding disorder may make the bleeding problems worse.

At times in their life, some symptomatic women may need to have gynaecological surgery or procedures. If this happens, it is important that this is managed in a team, with discussion between the woman, the Haemophilia Centre and the gynaecologist and/or surgeon.

Ideally your medical care team should work together on your health care and should include:

  • A gynaecologist
  • A haematologist specialising in bleeding disorders
  • A GP
  • A paediatrician or obstetrician, if relevant at the time.

Click here for more information on treatment for haemophilia

Read our booklets for more information on bleeding symptoms, factor level testing and a treatment plan:

Shorter/simpler version

Haemophilia testing in women and girls a guide
A guide to haemophilia testing in women and girls (genetic testing and factor level testing)

More comprehensive version

Haemophilia testing in women and girls
Haemophilia testing in women and girls: your questions answered

Download the fact sheets:
Haemophilia A and haemophilia B
Haemophilia in females (PDF, 1.1 MB)

Women's bleeding explained
Women's bleeding explained (PDF, 2.1 MB)

Working with your HTC
Haemophilia treatment and care for young women (PDF 1.3 MB) 

Date last reviewed: April 2023

Why do women and girls have genetic testing for haemophilia?

A normal factor VIII or factor IX level test will not tell females whether they carry the  gene alteration causing haemophilia. Some females may have normal factor levels, but still carry the gene alteration.

In genetics, all females who have the gene alteration causing haemophilia are called 'carriers'.

A common time for testing whether a girl or woman is a carrier is when she reaches childbearing age and can understand what will happen with testing and what it means and make the decision for herself.

Finding out whether she has the gene alteration is a process which will take time, sometimes many months. This may involve:

  • Discussion with a haemophilia team specialist and/or genetic counsellor
  • Weighing up the pros and cons of genetic testing with advice and support from specialists, counsellors and other experts
  • Looking at the family tree to identify other family members who may have the gene alteration
  • Blood tests for other affected family members (eg, a man with haemophilia) to identify the particular genetic mutation causing haemophilia in her family
  • Blood tests for the woman or girl to see if she has the same family genetic mutation
Many people find that undertaking these tests gives them a lot to think about. The Haemophilia Treatment Centre can help with information and advice about genetic testing and can provide a referral to a genetic counsellor, if needed. Women, their partner, family or parents of girls can talk to the Haemophilia Treatment Centre or genetic counsellor individually or together prior to testing.

Where can I have a genetic test?

Usually your state or territory clinical genetics service or your Haemophilia Treatment Centre (HTC) will undertake your genetic testing. They can also provide genetic counselling

They will use a specialist laboratory to analyse the results. You will need a referral. 

If you are speaking to your general practitioner (GP) about genetic testing, ask them to refer you to an HTC for diagnosis. If your GP is reluctant to refer you for genetic testing, you can request a referral to a clinical genetics service to discuss your options.

What if I change my mind?

If a person starts exploring genetic testing but decides against it, there is no obligation to complete the process.

For more information about genetic testing, see the Policies and Position Statements on the Human Genetics Society of Australasia web site

For more information about testing for haemophilia before birth, read the section in Pregnancy.

For more information about genetic testing for haemophilia,


Or read our booklets:

Shorter/simpler version
Haemophilia testing in women and girls a guide
A guide to haemophilia testing in women and girls (genetic testing and factor level testing)

More comprehensive version

Haemophilia testing in women and girls
Haemophilia testing in women and girls: your questions answered

Finding out you carry the gene
Read more about the experiences of women in our Finding out you carry the gene booklet 

Date last reviewed: September 2023

How do I plan a family with haemophilia?

For people with haemophilia or women who carry the gene, planning a family can raise a number of questions:

  • Will their children have haemophilia or carry the gene alteration?
  • If so, how will this affect them?
  • How can they find out?
  • What are the options for planning a family?
  • How can a mother who is a 'carrier' plan for a safe pregnancy and delivery?
  • Who will help with all of this?

Who can help?


  • The team at the Haemophilia Treatment Centre can help with information and advice about haemophilia, having children, genetics and genetic testing.
  • The Haemophilia Treatment Centre can provide a referral to a genetic counsellor or other counselling, if needed.
  • The woman, her partner and family can talk to the Haemophilia Treatment Centre or the counsellor individually or together. Many find this helpful.
  • A general practitioner (GP) or any other doctor can also provide a referral to a genetic counsellor or other counselling.
It may be useful to review the information about how haemophilia is passed on to children.

For more information on inheriting haemophilia, see HAEMOPHILIA INHERITANCE

Often an understanding of haemophilia is based on memories of a brother, father or grandfather’s experience. Treatment for haemophilia has improved a great deal over the years. It can be valuable to speak with a Haemophilia Treatment Centre or other haemophilia families to learn more about current treatments and to see how things have changed.  

Date last reviewed: September 2023

How do I prepare for pregnancy?

With good management, women who carry the gene alteration causing haemophilia gene have no more problems with delivering a healthy baby than other mothers. However, it is very important to plan and prepare as much as possible.

This involves:

  • If planning a pregnancy, discussing this with a haemophilia specialist. If discussing family planning, they may refer to a genetic counsellor
  • When the pregnancy is confirmed, contacting the Haemophilia Treatment Centre for advice on local obstetric services with experience of haemophilia
  • Asking the haemophilia and obstetrics teams to consult with each other to plan for a smooth and safe pregnancy and delivery and care for the newborn
  • Checking with the Haemophilia Treatment Centre before having any invasive procedures, such as chorionic villus sampling or amniocentesis
  • Discussing suitable choices for anaesthesia, especially an epidural, with the Haemophilia Treatment Centre and obstetrics teams
  • A normal vaginal delivery is usually recommended unless there are obstetric complications
  • Your HTC and your obstetrics team will work together to prepare a birth plan that is specific to you and your baby.

Identifying the sex of the baby

If a pregnant woman knows she carries the gene alteration causing haemophilia, it is advisable to determine the sex of the baby before birth, preferably with a non-invasive test with minimal risk to the fetus, such as ultrasound.

  • A male baby is more likely to be affected by severe haemophilia than a female.
  • The woman and her partner can choose if they want to be told the sex of the baby or not before delivery even if the haemophilia and obstetric teams are aware.
  • If neither the couple nor the medical staff know the sex of the baby and no other genetic testing of the fetus has been carried out, the pregnancy and birth will be managed as if the baby has haemophilia to ensure the baby is delivered safely.

Testing for haemophilia before birth

For a woman or couples who wish to test for haemophilia before birth, there are two main testing options:

  • Prenatal diagnostic testing: a test during the pregnancy to check the sex of the baby. If it is male, further testing can check for the family gene mutation or alteration, which will show if the baby has haemophilia
  • IVF with pre-implantation genetic diagnosis (PGD): using IVF technology to test embryos for the family gene alteration, before embryo implantation and pregnancy.

For these options to be available the gene alteration in the family must be known.

Prenatal diagnostic testing to check for the family gene alteration also involves testing with a procedure such as:

  • Amniocentesis: testing the amniotic fluid that surrounds the fetus in the uterus
  • Chorionic villus sampling (CVS): testing the placenta that connects the fetus to the mother’s uterus.

These tests are invasive and have a small risk for the mother and the fetus. 

A genetic counsellor can explore these reproductive options with the woman or the couple in further detail, along with any implications. There can be substantial costs for these tests and procedures, and it is recommended to clarify this and options for support beforehand. 

If a pregnant woman has or suspects she has a history of haemophilia in her family and does not know if she carries the gene alteration, it is important to let the obstetrics team know so that they can plan a safe delivery of the baby with the haemophilia team.


Date last reviewed: September 2023

What tips do others have?

  • Stay in regular contact with your local Haemophilia Treatment Centre (HTC) team and make sure you keep up with anything new. The HTC is there to help and can give you advice or talk over any problems or concerns
  • Keep in touch with your Haemophilia Foundation for updates on new information and enjoy a chat with other women who know what it’s like.
  • Bring HFA booklets with you to any medical, health or dental appointments. You can use them to help answer questions you might be asked. Your HTC might also have specific brochures you can take with you, for example, on surgery or dentistry if you have a bleeding disorder.
  • Make sure you know what type of bleeding disorder you have and how severe it is.
  • If you are registered for the ABDR, ask the Haemophilia Treatment Centre to organise an ABDR patient card for you. The ABDR patient card explains your diagnosis, what treatment you should be given and who should be contacted for further advice. Keep the card on you for quick reference.
  • Show your other doctors, dentist, and health care providers your ABDR patient card and ask them to liaise with your Haemophilia Treatment Centre. This will help with getting appropriate treatment. It will also make it easier to obtain treatment if you need it when you are away from your usual hospital or Haemophilia Treatment Centre, for example, if you are travelling or have moved interstate or overseas. 
  • Always inform your doctor, dentist or surgeon if you have a bleeding disorder before having any medical, dental or surgical procedures, no matter how minor. 
  • Before you have any procedures, contact your Haemophilia Treatment Centre and discuss the medical support you may need to prevent bleeding complications. Where possible, plan this well ahead of time. The Haemophilia Treatment Centre team may also need to liaise with your surgical or dental team or other health professionals involved in your care to discuss the best approach for you individually and any pre- or post-treatment care you may need.
  • Before you start taking anything prescribed by your doctor, naturopath or other health practitioner check with them whether it is safe for someone with a bleeding disorder. Some medicines, vitamins and supplements can interfere with blood clotting and healing, or can irritate your mucous membranes such as your nasal passages or stomach lining. This includes some herbal and homeopathic medicines and others available over-the-counter, such as aspirin and non-steroidal anti-inflammatory drugs like ibuprofen. Speak with your haematologist or your pharmacist about which medicines you need to be cautious with or avoid.  

Date last reviewed: September 2023
Adapted From:

Haemophilia. Rev. edn. Melbourne: HFA, 2023 2.5MB

Living with mild haemophilia: a guide. Melbourne: HFA, 2011 2.95MB


Australian Bleeding Disorders Registry. Annual Report 2020-21. Canberra: National Blood Authority, 2021. [PDF, 1.7MB]

Australian Haemophilia Centre Directors' Organisation. Guidelines for the management of haemophilia in Australia. Canberra: National Blood Authority, 2016.

Hermans C, Kulkarni R. Women with bleeding disorders. Haemophilia. 2018;24(Suppl. 6):29-36.

World Federation of Hemophilia. Guidelines for the management of hemophilia. 3rd edn. Haemophilia 2020; 26(Suppl. 6): 1-158.


Some sections in this publication were originally published by the World Federation of Hemophilia (WFH) and have been adapted with permission. The WFH is not responsible for any inaccuracies in content different from the content of the original English editions.


Many thanks to the HFA Women with Bleeding Disorders Consumer Review Panel and the Mild Haemophilia Health Professional Review Panel for their suggestions on topics and content to include.

This resource was reviewed by
Bleeding disorder community representatives from HFA Haemophilia Consumer Review Group (individuals not named for privacy reasons).

Australian Haemophilia Centre Directors’ Organisation: Dr Janice Chamberlain, Dr Liane Khoo. 
Australia and New Zealand Haemophilia Psychosocial Group: Kathryn Body, Jane Portnoy.
Australia and New Zealand Physiotherapy Haemophilia Group: Cameron Cramey, Alison Morris.
Australian Haemophilia Nurses’ Group: Jaime Chase, Alex Klever, Stephen Matthews, Robyn Shoemark.
Haemophilia Foundation Australia: Sharon Caris, Suzanne O'Callaghan.

We are also grateful to Clinical A/Prof Kristi Jones, Senior Staff Specialist in Clinical Genetics, The Children’s Hospital at Westmead, Sydney, and Melbourne Genomics for their suggestions and advice. 


Date last reviewed: September 2023

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.