title: Stage-dependent fetal umbilical blood flow changes induced by laser therapy and amniodrainage in twin-to-twin transfusion syndrome.
abstract: OBJECTIVE
  To estimate changes in umbilical blood flow (UBF) and Doppler indices in pregnancies complicated by twin-to-twin transfusion syndrome (TTS) treated with either laser therapy or amniodrainage, and to evaluate the influence of the presence of hemodynamic deterioration prior to therapy, as determined by the Quintero stages of severity.
  
  
  METHODS
  Forty-eight cases of TTS were included, and further classified into severity Stages I or II (absence of critically abnormal Dopplers (CAD), n = 22) and Stages III or IV (presence of CAD or hydrops fetalis, n = 26). In Stages I-II, 14 cases were treated with laser and eight with amniodrainage, and in Stages III-IV, 17 were treated with laser and nine with amniodrainage. Differences in the UBF, umbilical artery pulstility index (UA-PI) and ductus venosus pulsatility index (DV-PI) were estimated for both groups of severity before and after both treatments. Eleven normal monochorionic pregnancies were evaluated as controls.
  
  
  RESULTS
  In recipients, UBF was significantly higher with respect to controls regardless of the stage, while donors had a significant decrease in UBF, but only in Stages III-IV. After laser treatment no changes were observed in fetuses in Stages I-II. In Stages III-IV, recipients showed a significant reduction in the DV-PI (mean DV-PI 1.31 +/- 0.18 vs. 1.05 +/- 0.22; P = 0.005) whereas donors showed a significant increase in the UBF (mean UBF 134 +/- 36 mL/min vs. 195 +/- 25 mL/min; P < 0.001) and in the DV-PI (mean DV-PI 0.99 +/- 0.26 vs. 1.36 +/- 0.42; P = 0.002), and a reduction in the UA-PI (mean UA-PI 1.86 +/- 0.41 vs. 1.58 +/- 0.30; P = 0.01). After amniodrainage only donor fetuses in Stages III-IV showed an increase in UA-PI (mean UA-PI 1.54 +/- 0.35 vs. 1.72 +/- 0.40; P = 0.015). No other changes were observed in any of the parameters studied.
  
  
  CONCLUSIONS
  Laser therapy induces consistent hemodynamic variations in TTS mainly manifested in Stages III-IV.
authors.affiliation: Fetal Medicine Unit, Department of Obstetrics and Gynecology, Vall d'Hebron University Hospital, Universitat Autonoma de Barcelona, Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Becker
authors.forename: E
authors.initials: E
authors.lastname: Hernandez-Andrade
authors.forename: B
authors.initials: B
authors.lastname: Muñoz-Abellana
authors.forename: R
authors.initials: R
authors.lastname: Acosta
authors.forename: L
authors.initials: L
authors.lastname: Cabero
authors.forename: E
authors.initials: E
authors.lastname: Gratacós
mesh_terms: D000649:Amniocentesis; D005260:Female; D005330:Fetofetal Transfusion / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery / Q000628:therapy*; D005865:Gestational Age; D006801:Humans; D017075:Laser Coagulation; D011184:Postoperative Period; D011247:Pregnancy; D011446:Prospective Studies; D011673:Pulsatile Flow; D012039:Regional Blood Flow; D012720:Severity of Illness Index; D018608:Ultrasonography, Doppler / Q000379:methods; D014469:Umbilical Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology; D014470:Umbilical Cord / Q000098:blood supply*