title: The role of Doppler studies in predicting individual intrauterine fetal demise after laser therapy for twin-twin transfusion syndrome.
abstract: OBJECTIVE
  To investigate the role of Doppler studies in predicting individual fetal demise in patients scheduled for selective laser photocoagulation of communicating vessels (SLPCV) for twin-twin transfusion syndrome (TTTS).
  
  
  METHODS
  Doppler studies of the umbilical artery, umbilical vein, ductus venosus, tricuspid valve regurgitation and middle cerebral artery were performed in the donor and recipient twins before and 24 hours after SLPCV. Results were analyzed cross-sectionally and longitudinally. As multiple comparisons were made, an a priori alpha rejection was set at P < 0.001.
  
  
  RESULTS
  One hundred and ten consecutive patients were available for analysis. Overall fetal survival was 68.6% (151/220) with at least one survivor in 88.2% (97/110) of cases. Absent or reversed end-diastolic velocity in the umbilical artery of the donor twin was the only preoperative Doppler result predictive of intrauterine fetal demise (IUFD) (10/15, 66.7%, P < 0.001). Postoperatively, reversed flow during atrial contraction in the ductus venosus of the donor twin showed a trend towards prediction of IUFD of this fetus (4/5, 80%, P = 0.007). No other Doppler studies, including the longitudinal analyses, were predictive of IUFD.
  
  
  CONCLUSIONS
  Our data suggest that preoperative absent or reversed end-diastolic velocity in the umbilical artery may be useful in predicting individual fetal demise of the donor twin in TTTS patients scheduled for SLPCV. This may reflect the role of decreased individual placental mass that may be associated with some donor twins. The inability of other Doppler studies to predict individual IUFD may be explained preoperatively by the effect of the interfetal vascular connections on the individual Doppler signals and postoperatively by the effect of surgery or the timing of the assessment. Our findings may be important in patient counseling, in furthering understanding of the disease, and perhaps in improving surgical technique.
authors.affiliation: Florida Institute for Fetal Diagnosis and Therapy, St. Joseph's Women's Hospital, Tampa, FL, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Martínez
authors.forename: C
authors.initials: C
authors.lastname: Bermúdez
authors.forename: C
authors.initials: C
authors.lastname: Becerra
authors.forename: J
authors.initials: J
authors.lastname: López
authors.forename: W J
authors.initials: WJ
authors.lastname: Morales
authors.forename: R A
authors.initials: RA
authors.lastname: Quintero
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D005313:Fetal Death / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005330:Fetofetal Transfusion / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D005865:Gestational Age; D006801:Humans; D017075:Laser Coagulation / Q000379:methods*; D008137:Longitudinal Studies; D011182:Postoperative Care; D011247:Pregnancy; D011256:Pregnancy Outcome; D011295:Prenatal Care / Q000379:methods; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging* / Q000502:physiology