Recently a women in her late 40s presented to our hospital with a complaint of reduced exercise capacity and "heavy legs". Her only medication was her birth control pill. Her evaluation revealed a large thrombosis that orginated in her IVC just below the level of the renal veins and extended down into both of her femoral veins.
It is well documented that oral contraceptive pills (OCPs) increase the risk of thrombosis in women. Oral contraceptives are one of the most commonly prescribed pills the world and I think it is worthwhile to review what the risk of thromobis is.
There is no hard and fast data to say exactly how much OCPs increase the risk of thrombosis. Hematologists I have spoken with say that there is an increased risk that increases with age. Obviously there is an even greater risk in women with thrombophilia. Meanwhile there is certainly no evidence that every women who wants to use an OCP should have laboratory testing for thrombophilia. We also know that this risk increases with tobacco abuse.
Of course there are also many benefits of OCPs including desired birth control and reduction in ovarian cancer.
Overall I think we need to be reminded to advise our female patients of the risk of thrombosis with OCPs. We need to do a thorough personal and family history to look for anything that might suggest a thrombophilia. We should also be ready to investigate these women when they complain of anything that might suggest they have developed a thrombus.