Once again, because the placenta functions as a filter between mother and child, it depends on the free flow of blood from both parties to work efficiently. Because thrombophilia accelerates the bodyÕs tendency to form blood clots, the result could lead to a less permeable placenta, which would then be less able to facilitate the absorption of the neighboring blood supply. Although the vast majority of placentas experience a small degree of clotting naturally, significant clotting can lead to diminished supplies of oxygen and essential nutrients to the fetus. This in turn leads to some of the most serious complications of pregnancy, such as preterm labor and preterm birth, growth restriction, fetal death, placenta abruption (detachment), cerebral stroke, cerebral palsy, pre-eclampsia, maternal brain injury, and even maternal death.