OBJECTIVES: We investigated whether open-heart surgery with the use of extracorporeal circulation has an impact on menstrual bleeding.

METHODS: The menstrual bleeding pattern was registered in fertile women undergoing open-heart surgery in 2010-12. Haematocrit and 24-h postoperative bleeding were compared with those of men undergoing cardiac surgery.

RESULTS: Women (n = 22), with mean age of 36 (range 17-60) years, were operated on and hospitalized for 4-5 postoperative days. The mean preoperative haematocrit was 40% (range 32-60%), and mean haematocrit at discharge was 32% (range 26-37%). Mean postoperative bleeding in the first 24 h was 312 (range 50-1442) ml. They underwent surgery for atrial septal defect (n = 5), composite graft/David procedure (n = 4), pulmonary or aortic valve replacement (n = 6), myxoma (n = 2), mitral valvuloplasty (n = 2), ascending aortic aneurysm (n = 1), aortic coarctation (n = 1) and total cavopulmonary connection (n = 1). Unplanned menstrual bleeding (lasting 2-5 days) was detected in 13 (60%) patients. Of them, 4 were 1-7 days early, 4 were 8-14 days early, 3 were 1-7 days late and 2 had menstruation despite having had menstrual bleeding within the last 2 weeks. None had unusually large or long-lasting menstrual bleeding. Ten women took oral contraceptives, 8 of whom had unexpected menstrual bleeding during admission. Men (n = 22), with a mean age of 35 (range 17-54) years, had mean bleeding of 331 (range 160-796) ml postoperatively, which was not statistically significantly different from the women's. The mean preoperative haematocrit was 40% (range 29-49%) among men, while haematocrit at discharge was 32% (28-41), not significantly different from that seen in the female subgroup.

CONCLUSIONS: Menstrual bleeding patterns are disturbed by open-heart surgery in the majority of fertile women. Nevertheless, the unexpected menstrual bleeding is neither particularly long-lasting nor of large quantity, and the postoperative surgical bleeding is unaffected. We recommend that information about menstrual cycle disturbances related to cardiac surgery be provided, but no special precautions be taken, when operating on women of fertile age.