- Women who smoke should not use oral contraceptives really at any age, so we know that those two things are huge synergistic risk factors for stroke in younger women, and just adding the blood type to this is another factor that could certainly be a part of a risk profile, but I think there's probably still more work that needs to be done. I'm not sure that clinical practice is really gonna change based on this preliminary data. I think this is really exploratory and will lead to a lot of more interesting, larger studies of stroke in young women.