Scientists have uncovered a cause of heavy menstrual bleeding that offers hope for women living with the condition. Image Istock-46569523-AndreyPopov Researchers at the University of Edinburgh have identified a key protein that could explain heavy bleeding and pave the way for new treatments that avoid the need to take hormones. They identified a key protein that could explain heavy bleeding and pave the way for new treatments that avoid the need to take hormones. Heavy bleeding affects one in three women and can lead to severe anaemia – where there are not enough red blood cells to carry oxygen around the body. Hormones Current therapies are hormone based and often prevent pregnancy. Hormonal treatments can result in side effects and in many cases, women experiencing heavy periods may have to go undergo hysterectomy. Researchers studied the womb lining, known as the endometrium. This is shed during menstruation, leaving behind a wound-like surface that must heal to limit blood loss. HIF-1 levels They discovered that lowered levels of oxygen – known as hypoxia – stimulates production of a protein called HIF-1, which drives repair of the womb lining. Women with heavy periods had reduced levels of HIF-1 compared with women with normal blood loss, the findings showed. Tests on mice using a drug to boost levels of HIF-1 led to improved tissue repair and reduced blood loss. The results offer hope for therapies, scientists say. The study, published in Nature Communications, was primarily funded by Wellcome with support from the Medical Research Council, the Academy of Medical Sciences and Wellbeing of Women. Related links Original paper MRC Centre for Reproductive Health Publication date 31 Jan, 2018