PAI-1, tPA, TFPI, and HEECs in Uterine Hemostasis

HECC Study

We are seeking participants for a study of menstruating individuals with and without heavy menstrual bleeding.  The purpose of this study is to understand the role of different clotting factors in controlling uterine bleeding and the role of a certain cell type (endometrial endothelial cells) in regulating those clotting factors. 

Participants will attend one enrollment visit, scheduled at their convenience.  At that visit each participant will be given a menstrual cup and a form on which to indicate how many pads/tampons they use each day.  Participants will have a second visit on the first day of their next period, where they will have a blood draw and will drop off a sample of menstrual blood, collected in the provided menstrual cup.  They will then return to drop off a sample of menstrual blood each day of that period.  The final visit will occur about 3 weeks after the first day of that same period, at which a sample of the uterine lining will be obtained using a very small, plastic tube.  At that visit each participant will be asked to return the form on which they noted how many pads or tampons they used during that period.


You may be eligible to participate in this study if you:

  • Are a regularly menstruating individual
  • Are 18 years of age or older
  • Are not currently pregnant or breastfeeding
  • Are fluent in English
  • Are not currently using hormonal birth control or a copper IUD


You will be compensated for each of the study procedure, including $25 for completing the pad/tampon diary, $25 for the blood draw, $10 for each day you bring in a sample of menstrual blood and $200 for the sample of uterine lining.  If you bring in menstrual blood every single day of your period you will be compensated an additional $75.

Contact Information:

To find out more information and to learn if you are qualified to participate, fill out the online form or call the Women’s Health Research Unit confidential recruitment line at 503-494-3666 or email us at