There are two reasons that thrombophilia is particularly dangerous to pregnant women. First, the pregnant woman is more likely to form clots in her body because pregnancy increases the general risk for clot formation. In women with thrombophilia this risk is magnified many times over. Second, pregnancy outcomes are dependent on a healthy placenta, and in women with thrombophilia the placenta may be adversely affected by excessive clotting, which then affects the pregnancy in various ways.
