ULTRASOUND DIAGNOSIS OF VASA PREVIA, ANTEPARTUM MANEGEMENT AND DELIVERY CARE

Abstract

During the second trimester prenatal screening, it is important to document the placental cord insertion, and if abnormality is suspected, transvaginal sonography using a doppler pulse-wave is essential. The fetal vessels found within 2 cm from the cervical os are considered vasa previa, and fetal vessels that are 2–5 cm from the cervical os should be classified as “low lying fetal vessels”. In both cases, there is a high risk of fetal hemorrhage after rupture of membranes, so the diagnosis should be confirmed at 28–32 weeks of pregnancy during an ultrasound examination. Early hospitalization (usually between 28–32 weeks of pregnancy) and delivery are planned. In the case of vasa previa, C-section is usually performed at 34–36 weeks of pregnancy in singletons, in dichorionic twins – at 33–34 weeks of pregnancy, and in the case of monochorionic twins – at 32–33 weeks. Low-lying fetal vessels may also be an indication for an early caesarean delivery.