Doppler umbilical artery studies in the twin-twin transfusion syndrome
Giles, W.B.; Trudinger, B.J.; Cook, C.M.; Connelly, A.J.
Obstetrics and Gynecology 76(6): 1097-1099
1990
ISSN/ISBN: 0029-7844 PMID: 2234720 Document Number: 364865
Eleven patients with twin pregnancies were identified as having twin-twin transfusion syndrome on the basis of like-sex twins with monochorionic placentation and umbilical venous blood hemoglobin differences exceeding 50 g/L at delivery. Umbilical artery velocity-time waveform studies had been performed in these pregnancies as part of a large series of 456 twin pregnancies. In all 11 cases, the systolic-diastolic (S-D) ratio differences between the twins were less than 1 unit (mean 0.4 +/- 0.2), indicating that in twin-twin transfusion, umbilical artery S-D ratios are concordant even in the presence of discordancy in fetal size.