- The real important takeaway is that smoking and oral contraceptives are a bad combination. And although the guidelines have typically said, women over 35 who smoke should not take oral contraceptives, I don't think that should ever be the combination. We see women much younger than 35 who come in, who are smokers, and use oral contraceptives and they have a stroke. So why, you know, put them at risk and give this somewhat arbitrary age cutoff of 35. So the blood group just adds another dimension to that. And it isn't like I was saying earlier it is information that a lot of people know about themselves and they could take more precautions, make sure they take their aspirin if they're on aspirin if they have a non O blood type and definitely to avoid cigarettes at all costs and if oral contraceptives are necessary and typically they are safe, just make sure that those are women who have no other vascular risk factors because that's going to be the best way to prevent another stroke.