Mise en évidence des anastomoses vasculaires par la vélocimétrie doppler dans les grossesses gémellaires monochoriales. Revue de la littérature à  propos de trois cas

Three cases of intermittent absent end-diastolic and reversed end-diastolic flow velocity (A/REDV) are reported in the proximal umbilical artery of the growth-retarded twin in monochorionic twin pregnancies. This typical doppler velocimetric pattern has been related to arterioarterial anastomoses in two cases of intra-uterine growth retardation and in one case of twin-twin transfusion syndrome. According to the literature, superficial arterioarterial anastomoses may be detected by doppler colour velocimetry in 75 to 85% of cases, while identification of arteriovenous connections is more difficult to be documented in vivo (50% of cases in experienced hands). The role of superficial vascular anastomoses, either arterioarterial or venovenous, and that of deep arteriovenous communications is now well documented in the main complications of monochorionic pregnancies, particularly for twin-twin transfusion syndrome, intrauterine growth retardation, intrauterine fetal death and acardiac twins.