We read with great interest the recent Society for Maternal-Fetal Medicine. Guideline regarding the diagnosis and treatment of twin-twin transfusion. We congratulate Dr Simpson and the Society for Maternal-Fetal Medicine Publications Committee on an excellent review of the topic. However, we find fault with the committee’s conclusions that laser therapy for twin-twin transfusion syndrome “is considered by most experts to be the best available approach to stage II-IV cases at <26 weeks’ gestation, but the metaanalysis data show no significant survival benefit.” The authors cite a Cochrane review that found the overall rate of death after laser to be similar to treatment with amnioreduction (48% vs 59%; relative risk [RR], 0.81; 95% confidence interval [CI], 0.65–1.01). However, the authors fail to cite the lower rate of perinatal death (26% vs 44%; RR, 0.59; CI, 0.40–0.87) and the lower rate of neonatal death (8% vs 26%; RR, 0.29; CI, 0.14–0.87) from the same metaanalysis. The original Cochrane review on the topic included a single randomized trial by Senat et al that was stopped early due to a significant overall survival benefit to laser therapy. The second Cochrane review included the randomized trial by Crombleholme et al –a trial that was stopped prematurely due to poor recruitment and a higher rate of death in recipient fetuses after laser therapy. Indeed, this later trial only enrolled 29% of the proposed sample size. The authors concluded that the outcome of this trial did not answer which treatment, amnioreduction or laser, was the superior therapeutic option. Despite the inclusion of the second trial, the overall rate of death approached statistical significance (95% CI, 0.65–1.01) in the most recent Cochrane review. Additionally, another metaanalysis that included 4 studies and >600 patients has been previously published in the same journal as the current committee guideline. The authors found that fetuses undergoing laser were more likely to survive (RR, 2.04; CI, 1.52–2.76), less likely to die in the neonatal period (RR, 0.20; CI, 0.15–0.40), and less likely to experience neurologic morbidity (RR, 0.20; CI, 0.12–0.33). Finally, a recent metaanalysis of cerebral injury following laser therapy vs amnioreduction was undertaken by van Klink et al. Four studies involving 357 children in the amnioreduction group and 269 children in the laser group were analyzed. Cerebral injury in liveborn infants in the amnioreduction group was 7.69-fold increased over that in liveborns in the laser group (95% CI, 2.78–20.0). When neonatal deaths were excluded from the analysis, infants from pregnancies treated with amnioreduction were still noted to exhibit a marked increase in neurologic injury (RR, 3.23; 95% CI, 1.45–7.14) when compared to the laser group.

It would therefore appear that multiple metaanalyses support the beneficial role of laser treatment for advanced cases of twin-twin transfusion.