Derivation of rate of arterio-arterial anastomotic transfusion between monochorionic twin fetuses by Doppler waveform analysis

Denbow, M. L., Taylor, M., Cox, P. and Fisk, N. M. (2004) Derivation of rate of arterio-arterial anastomotic transfusion between monochorionic twin fetuses by Doppler waveform analysis. Placenta, 25 7: 664-670. doi:10.1016/j.placenta.2004.01.027


Author Denbow, M. L.
Taylor, M.
Cox, P.
Fisk, N. M.
Title Derivation of rate of arterio-arterial anastomotic transfusion between monochorionic twin fetuses by Doppler waveform analysis
Journal name Placenta   Check publisher's open access policy
ISSN 0143-4004
1532-3102
0265-7023
Publication date 2004-08-01
Year available 2004
Sub-type Article (original research)
DOI 10.1016/j.placenta.2004.01.027
Open Access Status Not yet assessed
Volume 25
Issue 7
Start page 664
End page 670
Total pages 7
Place of publication London, U.K.
Publisher W.B. Saunders
Language eng
Subject 111401 Foetal Development and Medicine
111402 Obstetrics and Gynaecology
1114 Paediatrics and Reproductive Medicine
Abstract We aimed to determine rates of interfetal transfusion along arterio-arterial (AA) anastomoses in monochorionic twins in vivo from analysis of Doppler waveform patterns. Twenty-one monochorionic twin pregnancies in which an AA anastomosis was identified antenatally underwent serial Doppler velocimetry. Unidirectional AA anastomiotic flow rates increased with increasing gestational age (log y = 8 x 10(-9)x - 5 x 10(-8); p = 0.0002). The mean net rate of flow through an AA anastomosis at 28 weeks gestation was 7.6 x 10-(8) l/s (SD = 4.9 x 10(-8) l/s). This flow was significantly related to the distribution of arterio-venous (AV) anastomoses (p = 0.009) and birthweight discordancy (p = 0.006). We derived estimates of flow along individual AV anastomoses by assuming that net AA countertransfusion is shared equally among uncompensated AV anastomoses, and speculate that the median AV flow rate at 28 weeks is in the order of 6 x 10(-8) l/s.
Formatted abstract
We aimed to determine rates of interfetal transfusion along arterio-arterial (AA) anastomoses in monochorionic twins in vivo from analysis of Doppler waveform patterns. Twenty-one monochorionic twin pregnancies in which an AA anastomosis was identified antenatally underwent serial Doppler velocimetry. Unidirectional AA anastomotic flow rates increased with increasing gestational age (log y=8×10−9x−5×10−8; p=0.0002). The mean net rate of flow through an AA anastomosis at 28 weeks gestation was 7.6×10−8 l/s (SD=4.9×10−8 l/s). This flow was significantly related to the distribution of arterio-venous (AV) anastomoses (p=0.009) and birthweight discordancy (p=0.006). We derived estimates of flow along individual AV anastomoses by assuming that net AA countertransfusion is shared equally among uncompensated AV anastomoses, and speculate that the median AV flow rate at 28 weeks is in the order of 6×10−8 l/s. In conclusion, this study demonstrates that flow rates along AA anastomoses can be quantified antenatally. These are the first estimates of flow rates in vivo along placental anastomoses. Although AA net flows are modest, chronic unbalanced counterflow of this magnitude in the absence of compensatory superficial anastomoses could lead to significant haemodynamic compromise.
© 2004 Elsevier Ltd. All rights reserved.

Keyword Arterio-arterial anastomoses
Monochorionic twins
Doppler velocimetry
Q-Index Code C1
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
School of Medicine Publications
 
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