Fetoscopic laser coagulation of placental vascular anastomoses is significantly more effective than serial amnioreduction for severe twin-to-twin transfusion syndrome (TTTS) at midgestation, according to a study that ended early because of the clear benefit.
The randomized multicenter trial conducted in Europe involved 142 pregnant women. Compared with the amnioreduction group, the women receiving laser surgery had a significantly higher rate of survival of at least one twin to 28 days of age (76% vs 56%) and to 6 months of age (76% vs 51%).
In addition, the infants in the laser group were less than half as likely as infants in the amnioreduction group to develop cystic periventricular leukomalacia (6% vs 14%), were far less likely to have neurologic complications by 6 months of age (31% vs. 52%), had higher birthweights (1,757 g vs. 1,359 g), and were born 4 weeks later (median 33 weeks vs. 29 weeks).
While 11 women in the amnioreduction group requested and underwent pregnancy termination between 21 and 25 weeks' gestation (usually because of severe fetal complications), none in the laser group did so. The rate of pregnancy loss within 7 days of the procedure was higher in the laser group, but not significantly so.
The reason for the laser procedure's greater success seems to stem from its attempt to address the cause of TTTS, rather than amnioreduction's band-aid approach of preventing preterm delivery related to polyhydramnios and improving fetal hemodynamics by decreasing pressure on the placental surface.
The authors of an editorial in the same issue of New England Journal of Medicine concluded that perhaps the "simpler, safer, but less effective procedures, such as amnioreduction and septostomy, are preferred for cases with a good prognosis, and that technically challenging procedures, such as cord occlusion and laser therapy . . . should be reserved for cases with a poor prognosis."
Senat MV, Deprest J, Boulvain M, et al. Endoscopic laser surgery versus serial amnioreduction for severe twin-to-twin transfusion syndrome. N Engl J Med. 2004;351:136-144.
Fisk NM, Galea P. Twintwin transfusionAs good as it gets? N Engl J Med. 2004;351:2.