Hemophilia A in women
Fact-checked by Hemophilia A, a genetic bleeding disorder, is often underdiagnosed in women because of the historical misconception that it affects only men due to its inheritance pattern. While women were once considered only carriers, or genetic transmitters, of hemophilia A, growing evidence shows that those carrying the disease-causing mutation can also experience excessive bleeding.
In addition, hemophilia A in women may manifest differently than it does in men, with sex-specific symptoms such as heavy menstrual bleeding, as well as postpartum bleeding, or excessive bleeding after childbirth.
Given this, monitoring and care for women with a hemophilia A-causing mutation typically requires a more nuanced approach that extends beyond standard assumptions about carriers.
Can women have hemophilia A?
Like boys and men, girls and women can show symptoms of hemophilia A and be diagnosed with the rare disease, which is caused by a deficiency in a blood-clotting protein called factor VIII (FVIII).
About half of hemophilia A female carriers have FVIII levels below 50% — the normal range is 50%-150% — which may increase the risk of excessive bleeding and be classified as mild hemophilia. But even those with FVIII levels considered to be within the normal range can experience excessive bleeds.
This prompted researchers to propose a new nomenclature for hemophilia A female carriers. Those with FVIII levels below 40% of normal — the diagnostic threshold established in males — are considered to have hemophilia, with its severity depending on how low the levels are. While hemophilia A in women is often milder than in men, it can still cause significant bleeding and, in some cases, symptoms as serious as those seen in men.
Female carriers with FVIII levels above 40% are now classified as asymptomatic hemophilia A carriers if they don’t experience significant bleeds, and as symptomatic hemophilia A carriers if they do, even though their factor levels do not fit standard diagnostic expectations.
It is estimated that 28% of female carriers will have FVIII levels below 40%, and more than a quarter will have higher levels but significant bleeding. The new classification, therefore, is essential for appropriate monitoring and treatment of women formally diagnosed with hemophilia A and symptomatic hemophilia A carriers.
Identifying female-specific signs
While hemophilia A may result in similar symptoms in men and women, including joint bleeds, easy bruising, and excessive bleeding after dental work or surgery, women can experience additional, sex-specific complications.
Female hemophilia A symptoms may also involve heavy menstrual bleeding and excessive bleeding during pregnancy, labor, and/or delivery.
For girls and women with symptoms of hemophilia A, heavy menstrual periods are the most common manifestation. Among the signs of heavy menstrual bleeding in hemophilia A are:
- bleeding for more than seven days
- passing clots that are bigger in size than a bottle cap, or a grape
- needing to change a tampon and/or pad every two hours or less
Heavy menstrual bleeding should be treated as a major warning sign of hemophilia A, especially when it causes anemia, fatigue, missed school or work, or repeated visits for unexplained blood loss.
Hemophilia A in women also may cause bleeding with ovulation, which can result in bleeding into cysts, or fluid-filled sacs, naturally formed on or inside an ovary. This can cause pain and require urgent medical intervention.
Overcoming diagnostic biases and hurdles
Care for hemophilia A in women is often complicated by diagnostic delays that stem more from historical misconceptions than from a lack of symptoms. Women with bleeding symptoms are sometimes not tested because of the mistaken belief that females can only be carriers and cannot truly have hemophilia.
As a result, a symptomatic hemophilia A carrier may spend years being told that heavy periods or excessive bleeding are normal, even when those symptoms clearly interfere with daily life. A 2023 study showed that female hemophilia A patients and carriers have more frequent bleeding than male patients, but are less likely to receive standard FVIII replacement therapy to prevent or stop bleeds.Â
Better diagnosis of hemophilia A in women and identification of symptomatic carriers depend on taking a detailed bleeding history seriously, checking factor levels, considering genetic testing when appropriate, and referring patients to hemophilia treatment centers that understand female bleeding disorders.
Pregnancy, labor, and delivery protocols
Pregnancy creates its own set of challenges in hemophilia A because FVIII levels can rise during pregnancy and then fall rapidly after delivery. That initial rise, which may temporarily reduce bleeding risk, can sometimes hide the presence of hemophilia A in women who have not yet been diagnosed. This can leave undiagnosed women unknowingly at risk of postpartum bleeding once factor levels drop.
It is recommended that obstetric teams know the woman’s bleeding disorder status before delivery and coordinate closely with hemophilia specialists to create a plan for pregnancy, labor, delivery, and postpartum care.
That plan may include anticipating maternal bleeding risk, avoiding forceps or vacuum extraction during delivery when possible, and arranging newborn assessment. Continuing surveillance after birth is recommended instead of assuming the danger has passed once delivery is over.
In addition, if the unborn baby is a boy and could potentially have hemophilia A, a cesarean section may be considered to lower the risk of fetal bleeding during delivery.
Advocacy and long-term care management
Living with hemophilia A or being a symptomatic carrier can have a significant impact on a woman’s emotional well-being, sometimes causing stress, social isolation, and a reduced quality of life.
Advocacy is an important part of care for hemophilia A in women to reduce disparities in healthcare access.
Heavy menstrual bleeding, unusual bleeding after procedures, or excessive bleeding after childbirth are still often dismissed by many healthcare specialists. Speaking up, keeping track of symptoms, and finding clinicians known as hematologists, who have expertise in blood-related diseases, or healthcare professionals who take bleeding concerns seriously, can make it easier to get the right diagnosis and treatment plan.
Over time, women with hemophilia A and those considered to be symptomatic hemophilia A carriers may need support from several specialists, including hematology, gynecology, and obstetrics, especially when heavy menstrual bleeding or iron deficiency keeps returning. Primary care physicians also need to be proactive in treating women with hemophilia A.
Comprehensive follow-up through experienced hemophilia treatment centers can improve recognition, personalize treatment, and reduce the long-term burden of underdiagnosis and undertreatment of hemophilia A in women.
Hemophilia News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
