Hemophilia Characteristics Among Women and Girls Receiving Care in Specialized Treatment Centers in the United States

A diverse group of women

Hemophilia is a rare, inherited bleeding disorder in which the blood does not clot properly. Blood contains many proteins called clotting factors that can help to stop bleeding. People with hemophilia have low levels of either factor VIII (8) or factor IX (9) blood clotting proteins. Hemophilia A is caused by low levels of factor VIII and hemophilia B is caused by low levels of factor IX. Hemophilia can lead to excessive bleeding after an injury or trauma, as well as bleeding that can occur for no apparent reason.

Hemophilia primarily affects men, but women can have hemophilia, too. It was once thought that only men could have hemophilia and women could only pass on the gene that causes hemophilia to their children, without having hemophilia themselves. However, since the 1950s, it has been documented that while women and girls can have the same hemophilia symptoms as men, women experience unique complications because bleeding disorders can affect their reproductive health. The actual number of women and girls who have hemophilia and seek care for their condition is unknown. Knowing how many women and girls have hemophilia, and how they experience bleeding symptoms, can contribute to a greater understanding of their unique healthcare needs.

About This Study

Community Counts is a public health monitoring program that gathers and shares information about common health issues, medical complications, and causes of death that affect people with bleeding disorders cared for in U.S. Hemophilia Treatment Centers (HTCs). Researchers analyzed data from Community Counts on all women and men who attended an HTC between January 2012 and September 2020. The goals of the study were to,

  • Determine the number of women and girls with hemophilia who receive care at HTCs. In this study, researchers defined hemophilia using established criteria based on blood test results indicating low factor VIII or IX.
  • Determine the number of women and girls who have mild, moderate, and severe hemophilia.
  • Compare characteristics of women and girls with hemophilia to those of men and boys with hemophilia who received care at an HTC during the same time.

Main Findings

Number of Women and Girls with Hemophilia

  • During the study period 1,667 women and girls received care in an HTC and met the study criteria for hemophilia.
    • Severe hemophilia was rare, occurring in only 51 women and girls.
    • Moderate hemophilia was slightly more common, occurring in 79 women and girls.
    • Mild hemophilia was the most common, occurring in 1,537 women and girls.
  • In comparison to women and girls, nearly 14 times as many men and boys (more than 23,000) received care in an HTC and met the study criteria for hemophilia.

Differences Between Men and Women with Hemophilia

  • Women and girls were less likely than men and boys to have severe hemophilia or moderate hemophilia (only 8% of women and girls had severe or moderate disease, compared to 70% of men and boys).
  • 92% of women and girls had mild hemophilia, compared to 30% of men and boys.
  • Women and girls with hemophilia were older, more often White, and less often non-Hispanic than the men and boys with hemophilia.
  • Women and girls with hemophilia had fewer HTC visits than men and boys with hemophilia. This difference in visits was seen within people who had all three severity levels – mild, moderate, and severe.

Gaps and Future Directions

  • Almost 1 in 5 patients who met the study criteria for mild hemophilia was female, and these women and girls had fewer HTC visits than men and boys with mild hemophilia. These results underscore the need for specialty care for women with hemophilia.
  • On average, women and girls in the study were older than men and boys. Further research is needed to determine the age at which women and girls first receive treatment and whether they can access care when they need it. Delays in diagnosis and treatment for hemophilia can result in complications during pregnancy and childbirth.
  • This study used information collected from people who received treatment for hemophilia at federally supported HTCs between 2012–2020. Not all people with hemophilia receive treatment for their condition, and those with the condition may receive treatment at healthcare centers other than HTCs. More research is needed to find out how many women and girls have hemophilia in the United States, including those who were not included in this study.
More Information

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Miller CH, Soucie MJ, Byams VR, Payne AB, Sidonio RF (Jr.), Buckner TW, Bean CJ. Women and girls with haemophilia receiving care at specialized haemophilia treatment centres in the United States. Haemophilia 2021;27(6): 1037-1044. https://doi.org/10.1111/hae.14403