Assessment of uterine placental circulation in thrombophilic women.

Thrombophilia is associated with several complications of pregnancy including first and second trimester fetal loss, intrauterine fetal death, intrauterine growth restriction, preeclampsia, and placental abruption. Few studies have documented thrombotic lesions observed on the pathologic examination of the placenta in women with severe pregnancy complications. Moreover, a significantly higher rate of factor V Leiden and prothrombin G20210A gene mutations have been found in placentas with thrombotic events compared with normal placentas. In addition, clinical studies have been performed, using Doppler ultrasonography, to assess the uterine placental circulation in women with thrombophilia. Doppler studies of the umbilical artery in cases of intrauterine growth retardation have shown a high systolic to diastolic ratio (S/D) ratio, suggesting an increase in the resistance of the placental small vessels. When these placental vessels were examined after delivery, significant differences were found in comparison with placental vessels of normal pregnancies. Most of the Doppler studies of the umbilical and uterine arteries in pregnancies with thrombophilia were performed in women with antiphospholipid antibodies. The other pathologic conditions associated with thrombophilia and complications of pregnancy were published only recently. These few studies have demonstrated abnormal umbilical and uterine arteries blood flow in complicated pregnancies. Finally, few Doppler studies also suggest improved uterine placental circulation when women with thrombophilia received thromboprophylaxis.