Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content


Woman in a grey sweater

Why We Do Research

Women with bleeding disorders can experience complications, such as heavy menstrual bleeding (called menorrhagia) and bleeding after pregnancy that can affect their overall health. CDC collaborates with public and private organizations in conducting research to better understand bleeding disorders affecting women and girls.

Current research suggests that many cases of menorrhagia might be due to an underlying bleeding disorder, the most common of which is von Willebrand disease (VWD). A 2002 CDC study of obstetricians and gynecologists in Georgia found that only 4% of the doctors who responded would have considered VWD as a possible cause of heavy menstrual bleeding. Those doctors also thought that only about 1% of women with heavy menstrual bleeding might have VWD. However, studies in the United States and Europe have shown VWD to be much more common; from 16% to 37% of women with heavy menstrual bleeding have been found to have VWD. Women with bleeding disorders might be at an increased risk for other gynecological complications, such as ovarian cysts, endometriosis, fibroids, and miscarriage; however, more study is needed.

CDC conducts research to:

  • Learn more about the number of people with bleeding disorders and risk factors for complications.
  • Develop and implement interventions that will help prevent complications of bleeding disorders, such as bleeding after pregnancy.
  • Create and deliver health promotion messages to encourage early diagnosis and treatment to prevent unnecessary complications and to help women make informed decisions about their own health care.
  • Discover blood tests through laboratory analysis that can help identify people who might be at risk for complications from bleeding disorders.

Some areas of CDC research in bleeding disorders affecting girls and women include the following:

Universal Data Collection System for Women and Girls

The Universal Data Collection (UDC) System is a research project designed to study information from the medical records and blood specimens of people who have bleeding disorders. The goal of UDC is to reduce and prevent complications of bleeding disorders, such as a potentially needless hysterectomy and postpartum bleeding. Information is collected to help determine the rates and severity of disease complications, to identify high-risk populations for prevention programs, and to identify areas for future study.

During the last 15 years, the number of women and girls with bleeding disorders visiting federally funded hemophilia treatment centers (HTCs) for care has increased steadily (see Figure). As women and girls continue to seek care at HTCs, there is a need to learn more about the issues they face.

The goals of this effort are to:

  • Characterize generally women and girls with bleeding disorders who receive care at an HTC.
  • Characterize bleeding associated with events that occur only among women and girls, such as menstrual periods, pregnancy, and childbirth.
  • Investigate the kinds of services women and girls receive at HTCs.
  • Study the care provided to women and girls with bleeding disorders.

Currently, 25 HTCs are participating in the first phase of this new data collection effort. It is anticipated that this initiative will be expanded to all HTCs in the future.


The numbers of female patients seen at Hemophilia Treatment Centers has increased more than 50% over the past 10 years. This includes women with von Willebrand disease, Factor VIII deficiencies and other rare factor deficiencies.

Harris Interactive Survey

Collaborating with the National Hemophilia Foundation (NHF), CDC engaged Harris Interactive to conduct a national, Internet-based market research survey of young women 18 through 25 years of age. The objective of this survey was to learn more about perceptions of menstrual periods and to measure awareness and recognition of a bleeding disorder. These survey findings will help CDC determine effective and innovative ways to reach young women and encourage the early diagnosis of a bleeding disorder such as VWD. CDC and NHF will design the appropriate messages, materials, and strategies to raise awareness, educate, and influence behavior. The messages and materials developed will be provided to the community through peer education, social networking, print, web, public service announcements, magazine articles, and local NHF chapters.

Women’s Treatment and Management Study

Menorrhagia is a common clinical problem among women. The underlying cause is not identified in 50% of cases; therefore, women might have undiagnosed VWD or another blood disorder. The majority of women with uncontrolled menorrhagia undergo a hysterectomy or other surgical procedures to relieve excessive bleeding. In this study, two noninvasive therapies―desmospressin and tranexamic acid―were compared. Both therapies were found to (1) reduce menstrual blood loss, and (2) improve the quality of life for women who had menorrhagia and abnormal laboratory findings. However, tranexamic acid was shown to have a greater effect.

Learn more about this research »

Provider Survey with the American College of Obstetrics and Gynecology

Obstetricians and gynecologists are generally the first healthcare providers to encounter a woman with menorrhagia. However, they are generally unlikely to initially consider an underlying blood disorder as the cause of heavy menstrual bleeding. To learn more, CDC has partnered with the American College of Obstetrics and Gynecology (ACOG). A national survey of obstetricians and gynecologists is underway that will evaluate their knowledge, attitudes, and practices concerning the role of blood disorders in menorrhagia.

Postpartum Bleeding Study

Postpartum hemorrhage (PPH), which is severe bleeding by the mother after delivery, is a significant public health problem and the leading cause of death among women during childbirth. Women with VWD are more likely to experience PPH and are 10 times more likely to die from childbirth complications than women without VWD.1 Through proper diagnosis and management of a bleeding disorder during pregnancy, potentially fatal complications can be prevented. CDC is conducting research to learn more about improving the health outcomes of women with bleeding disorders.

The goals of this research include:

  • Determining what percentage of women who had PPH have a bleeding disorder.
  • Identifying symptoms, risk factors, and other complications associated with bleeding disorders.
  • Assessing the adverse pregnancy outcomes associated with a bleeding disorder.

Study on Bleeding During Early Pregnancy

Few reports exist that describe pregnancy and childbirth complications among women with bleeding disorders. Some reports have suggested that women with VWD or other bleeding disorders are more likely to bleed during pregnancy and experience miscarriage and PPH. To learn more, CDC plans to study women who experience bleeding during early pregnancy to determine if an underlying bleeding disorder exists. If so, treatment to stop the bleeding can be given to prevent these poor pregnancy outcomes.

Screening Tool Evaluation Study

Referring women who have unexplained menorrhagia for testing to determine if they have a bleeding disorder is challenging from the perspectives of public health and cost. Justifying a recommendation for testing all women who have menorrhagia is difficult because most women tested will not have a bleeding disorder. From a financial perspective, these tests are expensive so this approach would be costly. To help address this issue, CDC has funded research to develop an eight-question screening tool to help identify women who would be most likely to benefit from the testing. This screening tool currently is being evaluated and ultimately might improve the health outcomes of women who have bleeding disorders by improving the chances for early diagnosis.

Feature Articles

Bleeding Disorders in Women
Heavy blood flow during menstrual periods can be a sign of a bleeding disorders.
(Published: December 8, 2014)


  1. James AH, Jamison MG. Bleeding events and other complications during pregnancy and childbirth in women with von Willebrand disease. J Thromb Haemost 2007;5:1195–9.