P05.04: Vascular resistance changes during amnioreduction in TTTS

Abstract

Our purpose was to investigate whether acute alterations of amniotic fluid volume affect fetal circulation in twin-to-twin transfusion syndrome (TTTS). The study group included 7 pairs of twin pregnancies complicated by TTTS. The alterations of pulsatility index (PI) in the umbilical artery and in the middle cerebral artery during 25 amnioreductions were evaluated. Color Doppler imaging was used to measure the changes of vascular resistance before and after the procedure. The PI values before and after amnioreduction were compared. The duration of procedure depended on the amniotic fluid volume removed during amnioreduction. Amniotic fluid volume reduction was carried out as long as normal value of maximal amniotic packet (MAP 2.0–8.0 cm) was achieved. The table presents the comparison of PI values in certain fetal vessels (UA and MCA) in the larger and smaller twin, as well as PI differences between twins before and after amnioreduction. Amnioreduction causes significant changes of blood flow resistance altering fetal circulation. In twin to twin transfusion syndrome the reduction of blood flow resistance in the umbilical artery may improve fetal condition and partially explain the success of serial amnioreduction therapy. Moreover, the assessment of blood flow changes in the MCA helps to choose optimal treatment. Supported by KBN 2 PO5E03027.