A Cochrane review included 2 studies with a total of 213 women. One study compared serial amnioinfusion with septostomy (71 pregnancies, 142 fetuses), and the other compared laser photocoagulation with serial amnioinfusion (142 pregnancies, 284 fetuses). Laser coagulation of anastomotic vessels resulted in less death of both infants per pregnancy (RR 0.49, 95% CI 0.30 to 0.79), less perinatal death (RR 0.59, 95% CI 0.0.40 to 0.87 adjusted for cluster) and less neonatal death (RR 0.29, 95% CI 0.14 to 0.61 adjusted for cluster) than in pregnancies treated with amnioreduction. There was no difference in perinatal outcome between amnioreduction and septostomy.
More babies were alive without neurological abnormality at the age of 6 months in the laser group than the amnioreduction groups (RR 1.66, 95% CI 1.17 to 2.35 adjusted for clustering). This difference did not persist beyond 6 months of age. There was no significant difference in the babies alive at 6 months with neurological abnormality treated by laser coagulation or amnioreduction (RR 0.58, 95% CI 0.18 to 1.86 adjusted for clustering).
Comment: The quality of evidence is downgraded by study quality (inadequate follow up).