New terminology for adverse events of fetal therapy: Re‐evaluation of the thoraco‐amniotic shunting in a Japanese study

AIM: Since fetal therapy has been newly developed, objective evaluation of adverse events (AE), all harmful events that are not always related to the procedures, has not yet been adequately reported. We established new terminology and tried to re-evaluate it based on the Japanese prospective thoraco-amniotic shunting (TAS) study. METHODS: From the literature, all complications that occurred with all fetal therapies were identified as a basis for developing the terminology. Grading was set from 0 to 5. Grade 3 was defined as the need for invasive treatment, such as surgery. Grade 4 was defined as life-threatening, and Grade 5 was defined as death of the mother or fetus. Then, one series of TAS that we had already reported was re-evaluated, including 24 cases with 37 procedures and 200 opportunities those could be evaluated AE after procedures. RESULTS: Grade 4 preterm rupture of the membranes was reported in only 1 of 24 cases. Catheter displacement was reported in 7, 2 and 11 cases, of Grades 1, 2 and 3, respectively. It was found that the double-basket catheter had some association with catheter displacement, but it was clear that there were no life-threatening AE. CONCLUSION: Newly developed AE criteria are now available for fetal therapy. They will contribute to the objective evaluation of AE of new fetal therapies in the future.