Key takeaways
Can women and girls have hemophilia?
Carrying the hemophilia gene vs. having hemophilia
Signs and symptoms of hemophilia in women worth paying attention to
How to find out if you are a carrier or have hemophilia
Periods, pregnancy, and postpartum with hemophilia or as a carrier
Finding support for women and girls living with hemophilia
Hemophilia is often thought of as a condition that only affects men and boys. And while hemophilia in women and girls is less common, many people still believe that women can only be carriers and cannot have hemophilia.
We now know that's not always the case. Women and girls can have hemophilia, and people who carry the hemophilia gene can experience bleeding symptoms as well.
Heavy periods, easy bruising, or prolonged bleeding after dental work, surgery, or childbirth may have many possible causes, but they are also symptoms that can occur in women and girls affected by hemophilia.
Understanding the difference between carrying the hemophilia gene and having hemophilia can help make sense of bleeding symptoms, inform conversations with healthcare professionals, and clarify whether additional evaluation, testing, or specialist care may be appropriate.
Please note this information may also be relevant to some trans and nonbinary people assigned female at birth. When discussing topics such as inheritance, menstruation, pregnancy, or childbirth, sex-based language is used because the biology involved is linked to X chromosomes and reproductive anatomy.
Can women and girls have hemophilia?
Yes, women and girls can have hemophilia, not just carry it, even though this is less common. Women and girls who are hemophilia carriers can also experience abnormal bleeding, even if they do not meet other criteria for hemophilia.
The common types of hemophilia (hemophilia A and B) are usually caused by the changes in the genes for clotting factor VIII (factor 8) or factor IX (factor 9). These genes are found on the X chromosome. As people assigned as male at birth only have one X chromosome, they are more likely to have hemophilia if their mother’s X chromosome is affected.
On the other hand, people assigned female at birth have two X chromosomes, so their chances of having hemophilia are lower. If only one X chromosome carries a hemophilia-related gene change, the other X chromosome may produce enough clotting factor to provide some protection from severe bleeding symptoms. People with this combination of genes are called hemophilia carriers.
Contrary to previous assumptions, people who carry the hemophilia gene can still have symptoms. Some women and girls can experience severe bleeding problems, much like men who have hemophilia, even if they are classified as carriers.
To counter outdated biases, a five-category framework was introduced in recent years to better understand how hemophilia affects women and girls. The framework combines the baseline levels of clotting factors VIII and IX (for hemophilia A and B, respectively) with personal bleeding history to acknowledge the differences in women and girls with mild, moderate, or severe hemophilia, plus symptomatic carriers and asymptomatic carriers.
Carrying the hemophilia gene vs. having hemophilia
Carrying the gene means having a hemophilia-related change in one X chromosome. However, some females can inherit two affected X chromosomes, or have one affected X chromosome and a problem with the other X chromosome. This can result in them having hemophilia.
Having hemophilia means that the affected X chromosome is unable to produce enough clotting factor. It is possible to be both a carrier and have hemophilia if you have low clotting factor levels. People with normal clotting factors may also experience abnormal bleeding.
Clotting factor levels are used to determine whether someone has mild, moderate, or severe hemophilia, or if they are a carrier. Hemophilia carriers can also be categorized as symptomatic or asymptomatic: those who experience abnormal bleeding, and those who don’t. However, asymptomatic hemophilia carriers can also experience other symptoms and burdens caused by the condition.
What is a hemophilia carrier?
A hemophilia carrier is someone who has a hemophilia-related change in just one of their X chromosomes. Carrier status can be inherited and may be passed to biological children.
Because people assigned female at birth typically have two X chromosomes, they are most often described as carriers when only one X chromosome has the hemophilia-related gene change. In contrast, people assigned male at birth have one X chromosome, so if they inherit a hemophilia-affected X chromosome, they will be diagnosed as having hemophilia. This is why males cannot be carriers of hemophilia; with only one X chromosome, an affected gene means having the condition (rather than carrying it).
The term “carrier” is not indicative of a person’s clotting factor levels or bleeding tendency, so we cannot assume that a carrier does not have hemophilia or is unaffected by symptoms.
Can a hemophilia carrier have symptoms?
Yes, contrary to outdated assumptions, hemophilia carriers can experience symptoms. Hemophilia carrier symptoms can include:
- Heavy menstrual bleeding
- Easy bruising
- Prolonged bleeding after procedures
- Postpartum hemorrhage (excessive bleeding)
Depending on their clotting factor levels, hemophilia carriers can also have hemophilia. Carriers with normal clotting factors may experience abnormal bleeding as well. A normal or near-normal clotting factor test result may not show the full picture. If you experience any unexplained symptoms or bleeding, speak to a healthcare professional about having further assessments.
70%
may experience abnormal bleeding
70% of genetic carriers of hemophilia may experience abnormal bleeding symptoms despite having normal factor levels.
Signs and symptoms of hemophilia in women worth paying attention to
The following bleeding patterns may be worth raising with a healthcare professional, particularly when you experience multiple or recurring symptoms:
- Heavy or prolonged menstrual bleeding
- Frequent or large bruises without a clear cause
- Bleeding that lasts longer than expected after dental work, surgery, injury, or childbirth
- Nosebleeds that are frequent or hard to stop
- Excessive bleeding after childbirth
It’s important to note that these symptoms are not a diagnosis. Heavy periods and bruising are common and may have many causes. Additionally, other inherited bleeding disorders, including von Willebrand disease, are more common than hemophilia. A healthcare professional will be able to recommend testing and evaluation that will help determine a diagnosis.
Before you discuss your symptoms with a healthcare professional, it’s a good idea to keep track of any symptoms or unusual bleeding patterns, how long the bleeding lasted, whether treatment was needed, and whether you have relatives who have similar experiences. These details will help your healthcare provider better understand your experience.
If you are wondering whether your symptoms could point to hemophilia or another bleeding disorder, you can read Hemophilia and von Willebrand disease explained.
How to find out if you are a carrier or have hemophilia
Hemophilia is usually diagnosed using two types of tests: screening tests to see if the blood is clotting properly, and clotting factor tests, also called factor assays, to determine if a person has hemophilia, what type it is, and how severe it is.
Your doctor may also use the ISTH Bleeding Assessment Tool to assess your bleeding tendency. This should not be used without a healthcare professional’s guidance, as they need to interpret and explain the results to you.
People who inherit bleeding disorders such as hemophilia should also have access to genetic counseling and testing. This can help explain how the gene is passed down, what the results may mean for you and your family, and help you plan for the future.
Speak to your doctor about what tests or evaluations may be right for you and ask whether a referral to a hemophilia treatment center (HTC) may help. You can also use resources on Connect to Care that may help you prepare for conversations with your healthcare team.
Questions to bring to an appointment
- Could my bleeding history suggest an inherited bleeding disorder?
- Should I have factor VIII and factor IX activity tested?
- Would a clinician-led bleeding assessment be useful?
- Could another condition, such as von Willebrand disease, explain my symptoms?
- Would genetic counseling help clarify my carrier status or family history?
- Should I see a hematologist or hemophilia treatment center?
Periods, pregnancy, and postpartum with hemophilia or as a carrier
If you are a woman or girl with hemophilia or a carrier, you may wonder how hemophilia can affect periods, pregnancy, delivery, and the weeks after childbirth. Yes, women with hemophilia can become pregnant and give birth, but pregnancy and delivery are important topics to discuss early with a care team that’s experienced in bleeding disorders.
Any unusual bleeding during these life stages should be noted and raised with a healthcare professional.
Can heavy periods be a sign of hemophilia or another bleeding disorder?
Yes, heavy periods can be one sign of a bleeding disorder, but heavy menstrual bleeding by itself does not mean you have hemophilia. However, if it is combined with other bleeding, iron deficiency, or a personal or family history of unusual bleeding, it should be discussed with a healthcare professional.
What should I know about pregnancy if I am a carrier or have hemophilia?
If you are planning for a family and you have hemophilia or are a carrier, you may wonder “how does hemophilia affect pregnancy?” A good place to start is by having a conversation with a healthcare professional with expertise in bleeding disorders. The conversation may involve questions about factor levels, genetic counseling, prenatal testing choices, delivery planning, anesthesia, and the newborn’s evaluation—it’s recommended that these discussions start before pregnancy or early in pregnancy.
There are certain ways hemophilia can affect pregnancy and childbirth. For example:
- Factor VIII can rise due to pregnancy, making it harder for tests to determine if a pregnant woman has hemophilia A.
- Factor IX is not affected by pregnancy, so this does not apply to people with hemophilia B.
- Factor XI (factor 11) deficiency is not hemophilia A or B, but it can be relevant during pregnancy as it may affect bleeding risk.
Make sure you speak to your doctor, hemophilia care team, or obstetrician to create a personalized pregnancy and delivery plan.
What about bleeding after childbirth?
People who carry the hemophilia gene are at risk for heavy bleeding after childbirth, and clotting factor levels that increased during pregnancy can fall during this time. It is important that your healthcare team is aware of your hemophilia status and history in order to plan for a safe delivery and postpartum follow-up.
Finding support for women and girls living with hemophilia
It is important that you feel supported throughout your hemophilia journey. A hemophilia treatment center (HTC) can help with specialist assessment and coordinated care. Advocacy and peer-support organizations may also offer programs for women, girls, carriers, caregivers, and gender-diverse people affected by bleeding disorders.
Here are some helpful organizations and resources:
- Foundation for Women & Girls with Blood Disorders (FWGBD)
- FAIR Time for Women (FTFW)
- Blood Sisterhood (Hemophilia Federation of America)
You can also learn more about HTCs and find one near you:
- Hemophilia Treatment Centers (World Federation of Hemophilia)
Take the next step with your care team
Women and girls can have hemophilia, and carriers can experience bleeding symptoms. If you recognize any of the signs and patterns described, speak to a healthcare professional about getting tested and evaluated.
Bring a short record of symptoms and procedures to the conversation. If specialist input is needed, ask about a hematologist or HTC. Consulting people with expertise in bleeding disorders can help you better understand the cause behind your symptoms.
Ready to have a conversation with your doctor or healthcare professional? Download the Doctor Discussion Guide to organize your questions and identify what you would like to discuss.
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Frequently asked questions
Can I bleed excessively even with normal factor levels?
Yes, a hemophilia carrier can have increased bleeding even when they have normal clotting factor levels. Factor testing is important, but it needs to be considered alongside personal bleeding history and other possible causes.
Can hemophilia carrier status be passed on to children?
Yes, a hemophilia-related gene change can be passed on to biological children. The chance and possible outcomes depend on the specific inheritance pattern. A genetic counselor can help you better understand your situation.
Is testing for hemophilia recommended before pregnancy?
Testing may be discussed before pregnancy when someone has carrier status, a personal bleeding history, or a family history of hemophilia. A care team can explain factor testing, genetic counseling, and reproductive testing options.
Can factor levels change over time?
Yes, clotting factor VIII often increases during pregnancy. A clinician may repeat testing when the timing or health context could affect interpretation.
Can women have hemophilia with no family history?
Yes, a woman or girl can have hemophilia even without a known family history because a new genetic change can occur or their family history of hemophilia may have been forgotten or unknown.
How many women and girls have hemophilia?
There are 1.6 female carriers for each man with hemophilia. However, the exact number of women and girls with hemophilia is not known, as many women with hemophilia remain undiagnosed.
Why is hemophilia more common in men than in women?
Hemophilia is more common in men because the gene mutations that cause hemophilia are located on the X chromosome. As people assigned male at birth only have one X chromosome, these people are more likely to have hemophilia if their mother’s X chromosome is affected. On the other hand, people assigned as female at birth have two X chromosomes, so their chances of having hemophilia are lower.
Why are women carriers for hemophilia?
Hemophilia carriers tend to have one X chromosome that’s affected by the hemophilia gene and one X chromosome that is not affected. This means hemophilia carriers are usually women, because people assigned female at birth have two X chromosomes, compared to people assigned male at birth, who only have one X chromosome.
More relevant articles
Keep reading
- /hemophilia/education/hemophilia-types-von-willebrand-disease
- /hemophilia/education/aging-with-hemophilia
- /health/education/types-of-blood-disorders
References
Bleeding Disorders Canada. Heredity of Hemophilia. Accessed September 28, 2026. https://bleedingdisorderscanada.ca/heredity-of-hemophilia/
Centers for Disease Control and Prevention. About hemophilia. Updated May 15, 2024. Accessed September 28, 2026. https://www.cdc.gov/hemophilia/about/index.html
Centers for Disease Control and Prevention. Diagnosing Hemophilia. Updated May 15, 2024. Accessed September 28, 2026. https://www.cdc.gov/hemophilia/testing/index.html
Centers for Disease Control and Prevention. Information on hemophilia for women. Updated May 15, 2024. Accessed September 28, 2026. https://www.cdc.gov/hemophilia/about/information-for-women.html
National Bleeding Disorders Foundation. MASAC Document 286: MASAC recommendations regarding diagnosis and management of inherited bleeding disorders in girls and women with personal and family history of bleeding. Accessed September 28, 2026. https://www.bleeding.org/healthcare-professionals/guidelines-on-care/masac-documents/masac-document-286-masac-recommendations-regarding-diagnosis-and-management-of-inherited-bleeding-disorders-in-girls-and-women-with-personal-and-family-history-of-bleeding
National Health Service. Great Ormond Street Hospital for Children. Factor XI Deficiency. Updated April 17, 2024. Accessed September 28, 2026. https://www.gosh.nhs.uk/conditions-and-treatments/conditions-we-treat/factor-xi-deficiency/
National Organization for Rare Disorders. Acquired Hemophilia A. Updated January 26, 2026. Accessed September 28, 2026. https://rarediseases.org/rare-diseases/acquired-hemophilia/
van Galen KPM, d’Oiron R, James P, et al. A new hemophilia carrier nomenclature to define hemophilia in women and girls: communication from the SSC of the ISTH. J Thromb Haemost. 2021;19(8):1883-1887. doi:10.1111/jth.15397