I am 27 years old, have had UC since I was 14. I have been on 150mg Imuran per day for about 4 years now. Although I was very worried about being on Imuran while I was pregnant with my son 2 years ago, my GI doctor told me that it would be much better for me and my baby to remain on the Imuran during pregnancy. I spotted during my first three months of pregnancy, which made me worry even more. My son turned out to be very healthy :) Well, my periods have become increasingly irregular since having my son. I lightly spot almost every day of the month and have about 4-5days per month of heavy bleeding. My bleeding seems to be worse after exercise. My family doctor had me go in for a pelvic ultrasound, which turned out to be normal. One of my lab results did show that I had low Von willebrand factor, which can cause irregular periods. I have an appointment with a hematolagist and a OB/GYN soon, but was wondering if any other women on Imuran have had similar bleeding problems? It seems like I've noticed irregular bleeding since being on Imuran. I'm wondering if there may be a correlation with Imuran lowing you Von willebrand factor in your blood. I am hesitant to switch medication because I have been in remission for 3 years now. Please let me know if you have a similar problem. Thanks!