Neurodevelopmental outcome after laser therapy for twin-twin transfusion syndrome

Abstract

TO THE EDITORS: We read with great interest the editorial from Moise 1 and agree with most concerns that were raised on the neurodevelopmental outcome in twin-to-twin transfusion syndrome (TTTS). However, some comments need further explanation, particularly those concerning our study. 2 First, the incidence of severe cerebral lesions in our study increased between day 1 and discharge from 10% to 14% in the TTTS group and from 2% to 6% in the no-TTTS group. 2 These numbers represent a one-third increase in the TTTS group and two-thirds increase in the no-TTTS group, contrarily to what is stated in the editorial. 1 Second, the high survival rate in our study is primarily due to the exclusion of TTTS cases with double intrauterine fetal death. 2 It therefore is not appropriate to compare our survival data with those of other studies that are based on different inclusion criteria. In fact, the results of laser treatment for TTTS in our center are similar to those of other large fetal medicine centers. 3 Third, inclusion criteria for laser treatment at our center consist of Quintero stage 1 disease with severe clinical symptoms of polyhydramnios or Quintero stage 2. 3 At our center, the percentage of TTTS pregnancies with stage 1 disease that are treated with laser is 10% to 17%, 2,3 which is similar to the percentage of stage 1 disease in the studies by Yamamoto et al 4 and Quintero et al, 5 10% and 20%, respectively, that were reported in the editorial. 1 Therefore, our results are not better, nor do we treat more stage 1 disease than in other large fetal medicine centers. A recent randomized control trial has shown that laser surgery leads to improved outcome compared with amnioreduction in TTTS stage 3-4 and in stage 1-2. 6 Whether expectant management in stage 1 disease is superior to laser surgery or amnioreduction has not been studied. However, given the frequent progression to higher stages 7 and the risk of premature delivery in stage 1 disease with severe clinical symptoms of polyhydramnios, we think that expectant management in these cases is unwarranted. In a series of 100 TTTS pregnancies that were treated with laser surgery at our center, the perinatal survival rate in stage 1 was 95% (19/20 infants), 3 and the intact