People used to think that only males developed hemophilia. Females were considered “carriers” of the disease, meaning they could pass it on to their children but didn’t have symptoms of hemophilia themselves. However, as scientists learned more about this inherited bleeding disorder, they discovered that females can have hemophilia symptoms, too.

Recognizing hemophilia is crucial for proper care. Here are some important facts to know about how the disease affects females.

1. Males and Females Have Different Genetics

There are two main types of hemophilia. People with hemophilia A have too little of clotting factor VIII (8), a protein that helps the blood clot. In hemophilia B there is too little of another clotting factor, factor IX (9).

Hemophilia is a genetic disorder. The genes that determine whether someone has either type of hemophilia are located on the X chromosomes. Females are born with two X chromosomes, whereas males are born with one X and one Y chromosome.

Males who inherit hemophilia only on their X chromosome will have signs of the disease. However, since females have two X chromosomes, there’s a good chance they’ll inherit hemophilia only one of them. Because they have another X chromosome with normal clotting genes, their symptoms are milder and sometimes go unnoticed. These individuals are known as carriers because they carry the mutated hemophilia gene, which they can pass on to their sons.

Though rare, some females with one hemophilia gene do have severe bleeding symptoms. In addition, some inherit hemophilia or other clotting disorders from both parents. As a result, both of their X chromosomes are affected.

Members of MyHemophiliaTeam have explained how they got the disease. “I am in fact a female with mild type B hemophilia,” said one member. “My father has it as well, and my mother has no traces of the disease or as a carrier throughout her family. I got it from a possible gene mutation.”

Overall, females may develop hemophilia under the following conditions:

• Both of their parents have a mutated hemophilia gene.
• They have one inactive X chromosome through a process called lyonization and the other X chromosome that carries a mutated hemophilia gene.
• They have a condition known as Turner syndrome, in which they have only one X chromosome instead of two.

Another bleeding disorder that’s more common in women, according to UC Davis Health, is called von Willebrand disease. Genetic testing and a review of your family history can help pinpoint the right diagnosis.

2. Symptoms Are (Usually) Milder in Females

Approximately 1 out of every 5 people being treated for mild hemophilia at hemophilia treatment centers (HTCs) are female, according to a study in the journal Haemophilia. However, the exact rate is difficult to determine because females may not be diagnosed with hemophilia as often as they should be.

“I was diagnosed just 10 years ago, almost by mistake when getting some bloodwork done, even though the symptoms were definitely there all of my life,” a member of MyHemophiliaTeam wrote.

Generally, hemophilia symptoms include:

• Bleeding into the joints and muscles
• Bruising easily
• Excessive bleeding after injuries
• Frequent nosebleeds
• Weaker bones and osteoporosis (a bone disease that causes bones to become weak and brittle)

Sometimes, females with hemophilia are misdiagnosed with arthritis. Bleeding into the joints can be difficult to detect and may limit the range of motion.

Females are considered carriers when they have more than 40 percent of the normal amount of clotting factor. Sometimes carriers have bleeding symptoms, and sometimes they don’t. Although rare, some females have severe hemophilia.

To help define hemophilia severity, the International Society of Thrombosis and Haemostasis classified hemophilia into five categories specifically for women and girls:

• Asymptomatic carriers — Those with more than 40 percent of the normal amount of clotting factor but no bleeding symptoms
• Symptomatic carriers — Those with more than 40 percent of the normal amount of clotting factor and bleeding symptoms
• Mild hemophilia — Those with 5 percent to 40 percent of the normal clotting factor level
• Moderate hemophilia — Those with 1 percent to 5 percent of the normal clotting factor level
• Severe hemophilia — Those with less than 1 percent of the normal clotting factor level

It’s important to look into your hemophilia risk if you have a family history of blood disorders, even if you have any noticeable symptoms.

3. Heavy Monthly Periods Can Be a Serious Concern

One of the first signs of undiagnosed hemophilia or other blood clotting disorders is heavy menstrual bleeding. Females with bleeding disorders may have bleeding that lasts for seven days or longer.

Other signs of a clotting disorder during menstruation include:

• Having low levels of iron
• Experiencing intense bleeding that interferes with daily activities
• Passing large clots (bigger than the size of a quarter)
• Needing to change pads or tampons each hour or sooner

According to UC Davis Health, women with clotting issues should be tested for anemia regularly so they can get treatment if needed.

One member of MyHemophiliaTeam shared that their periods were so bad, they ended up needing a hysterectomy (surgical removal of the uterus). “I had a hysterectomy at the age of 22. It did help with the bleeding issues that went along with my menstrual cycle. I very rarely have nosebleeds anymore, however, I do experience a lot of body aches and unexplained bruises,” the member wrote.

A hysterectomy is a major procedure, and after undergoing one, the recipient will be unable to become pregnant. More frequently, females with hemophilia who have menstrual problems use oral contraceptive pills and a medication called tranexamic acid to help control their bleeding.

4. Pregnancy and Childbirth Come With Greater Risks

It’s possible for individuals with hemophilia to have a successful pregnancy and childbirth. However, they need to be extra careful to maintain sufficient iron stores while pregnant. In addition, excessive bleeding when giving birth can be life-threatening.

Specialists from a hemophilia treatment center can work together with an obstetrician to take special precautions. In addition, the baby should be tested for hemophilia and connected with care if needed. Through special genetic tests, it is now possible to diagnose during pregnancy whether the baby would go on to develop hemophilia after birth.

5. Many Options Are Available for Managing Hemophilia

Basic hemophilia treatment options are the same for everyone with hemophilia, regardless of biological sex. In addition, doctors may prescribe birth control pills to help with heavy periods. Desmopressin acetate nasal spray is another option for individuals with low factor VIII or von Willebrand disease. If you want to become pregnant, it’s best to discuss your plans with your health care providers first so they can help you prepare for the best outcomes.

Women already have a greater risk for anemia (low levels of red blood cells), according to UC Davis Health. They’re also at four times higher risk for osteoporosis than men. These risks are even higher with hemophilia. It’s essential to monitor blood iron levels and bone density. Iron, calcium, and vitamin D supplements may be recommended. In addition, strength training can promote bone strength and help prevent osteoporosis, especially when started earlier in life.

If you have a history of hemophilia in your family, ask your doctor for medical advice on getting tested. With proper monitoring and treatment, you can help reduce any negative impacts on your quality of life.

Talk With Others Who Understand

MyHemophiliaTeam is the social network for people living with hemophilia and their friends and family members. Members come together to ask questions, give advice, and share their stories about life with hemophilia.

Are you a woman with hemophilia? If so, how has it affected your life? Share your experience below, or start a conversation by posting on your Activities page.