[Preeclampsia and antiphospholipid syndrome. Uterine artery Doppler evaluation].
INTRODUCTION: Women with persistently high resistance in uterine arteries have an increased risk of the subsequent development of preeclampsia. Doppler investigation provides a non-invasive method for the study of the uteroplacental blood flow. In pregnant women the antiphospholipid syndrome is associated to an increased risk of preeclampsia and complications related to uteroplacental insufficiency, and the role of uterine artery Doppler is discussed. CURRENT KNOWLEDGE AND KEY POINTS: In normal pregnancy, impedance to flow in the uterine arteries decreases with gestation, as the likely consequence of the physiologic change of spiral arteries into low-resistance vessels. In women with preeclampsia or related complications, the abnormal persistence of high resistance to flow in the uterine arteries correlates with maternal and neonatal outcome. In one study including patients with antiphospholipid syndrome, a high resistance index in the uterine arteries at 22-24 weeks gestation strongly predicted the subsequent development of preeclampsia. In another study including patients with lupus anticoagulant, persistent bilateral notches at 22-24 weeks gestation may identify preeclampsia and fetal growth restriction with a high sensitivity, specificity, positive and negative predictive value. The treatment may improve the uteroplacental blood flow and is a possible confounding factor which needs further evaluation. FUTURE PROSPECTS AND PROJECTS; In patients with antiphospholipid antibodies a higher impedance has been observed in the uterine artery, suggesting a possible vascular dysfunction precluding to impaired trophoblastic invasion and placental thrombosis, as probable mechanisms in the complications. If confirmed, these findings might have important implications for the management of these patients.