Preoperative prediction of the individualized risk of early fetal death after laser therapy in twin-to-twin transfusion syndrome

Objective: The aim of this study is to evaluate the independent and combined value of gestational age, fetal weight, fetoplacental Doppler, and myocardial performance index for the prediction of individual risk of early (≤7days) intrauterine fetal death (IUFD) after laser therapy in twin-to-twin transfusion syndrome (TTTS). Material and Methods: A consecutive series of 215 cases of TTTS treated with laser therapy in three centers was prospectively studied. Ultrasound evaluation within 24h of surgery included estimated fetal weight discordance, umbilical artery, pulsatility index (PI) and diastolic flow evaluation, middle cerebral artery PI and middle cerebral artery peak systolic velocity, ductus venosus PI and atrial flow assessment, and modified myocardial performance index. Logistic regression analysis was used to explore the association of preoperative parameters with IUFD. Results: Intrauterine fetal death occurred in 17 (7.9%) of the recipients and 33 (15.3%) donors (p=0.016). The only independent predictors of IUFD in recipients was the middle cerebral artery peak systolic velocity >1.5MoM (OR=22, p=0.015), but this event was present in only 3% of recipients. In donors, reverse end diastolic flow in the umbilical artery (OR=14.748, p=0.033), estimated fetal weight discordance (OR=1.054, p=0.036), and gestational age (OR=0.757, p=0.046) were independent predictors. Conclusion: In TTTS, preoperative fetal assessment can identify independent risk factors for early post-operative IUFD, particularly in donors. What's already known about this topic? IUFD after laser therapy occurs in 14% of TTTS. Factors that have been related with IUFD are gestational age, blood flow in the umbilical artery and middle cerebral artery, and cardiac function. What does this study add? This study provides data about prediction of the individual risk of early post-operative IUFD after laser placental coagulation for TTTS using preoperative data. The strongest predictor of fetal death is REDF in donor UA and elevated MCAPSV in the recipient twin.