We thank Dr Moise et al for their interest and congratulations for our Society for Maternal-Fetal Medicine (SMFM) clinical guideline on twin-twin transfusion syndrome. Dr Moise et al have a concern that not all data in the metaanalyses on this topic were reported in the SMFM clinical guideline. We provided details from both of the 2 randomized trials on twin-twin transfusion syndrome treated by laser, including tables representing the primary and several secondary outcomes. We also reported the results of the metaanalysis based on these 2 randomized controlled trials (RCTs). We believe that the recommendations provided in the SMFM clinical guideline primarily reflect data available from level-I sources, and are consistent with the data available from the published RCTs.

Regarding the metaanalyses, Roberts et al reported as the main result a nonsignificantly different rate of overall death (48% vs 59%; relative risk, 0.81; 95% confidence interval, 0.65–1.01) in the laser vs amnioreduction groups, respectively. Of course, there are many other outcomes reported, some of which are significantly better for laser (as Dr Moise et al point out) and some of which instead found no differences between groups (eg, babies alive at 6 months who needed treatment for major neurologic abnormality, 4% vs 7%; relative risk, 0.58; 95% confidence interval, 0.18–1.86). The metaanalysis by Rossi and D’Addario included only 1 of the RCTs and 9 nonrandomized series. Similarly, the metaanalysis by van Klink et al also included data mostly from non-RCT sources. These do not represent level-I data metaanalyses and are superseded by the available level-I data.

Society for Maternal-Fetal Medicine Publications Committee

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Contact: Beth Steele ( esteele@smfm.org )

Each member of the Society for Maternal-Fetal Medicine Publications Committee has submitted a conflict of interest disclosure delineating personal, professional, and/or business interest that might be perceived as a real or potential conflict of interest in relation to this publication and none have a conflict.