[Doppler waveforms patterns of vascular anastomoses in monochorionic twin pregnancies. A report of three cases and review of the literature].
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 arterio-arterial anastomoses in two cases of intra-uterine growth retardation and in one case of twin-twin transfusion syndrome. According to the literature, superficial arterio-arterial 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 arterio-arterial 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.
Lemerle
S
S
Service de gynécologie-obstétrique, hôpital Mère-Enfant, 38, boulevard Jean-Monnet, 44035 Nantes cedex 01, France.
Le Vaillant
C
C
Dubreil
C
C
Boog
G
G
D000328:Adult; D004200:Diseases in Twins / Q000000981:diagnostic imaging*; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging; D005330:Fetofetal Transfusion / Q000000981:diagnostic imaging; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011248:Pregnancy Complications / Q000000981:diagnostic imaging*; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D011272:Pregnancy, Multiple; D014430:Twins, Monozygotic; D018615:Ultrasonography, Doppler, Color; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging*