For patients with Factor V Leiden, which scenario significantly increases the risk of DVT?

The scenario that significantly increases the risk of deep vein thrombosis (DVT) for patients with Factor V Leiden is the combination of pregnancy or the use of oral contraceptives. Factor V Leiden is a genetic mutation that leads to increased clotting risk, and hormonal changes associated with pregnancy or the intake of oral contraceptives can compound this risk.

During pregnancy, there are elevated levels of estrogen, which can increase blood coagulability. Similarly, oral contraceptives contain estrogen hormones, which may enhance the propensity for blood clots in individuals already predisposed to thrombosis due to the Factor V Leiden mutation. Therefore, these factors play a significant role in promoting venous thromboembolism in affected individuals.

In contrast, while being male and over 40 does contribute to DVT risk, it is not specific to Factor V Leiden nor as compelling as the a hormonal influences mentioned. Exercise is generally protective against DVT and a low BMI typically does not correlate with increased risk in the same manner.