The outcomes of transient elevation of maternal liver enzymes preceding laser treatment for twin-twin transfusion syndrome

Background: A proportion of twin-twin transfusion syndrome (TTTS) patients may have elevated liver enzymes (ELEzs) before fetoscopic laser therapy, but the incidence of ELEzs before laser therapy and the association with the perinatal outcomes after laser therapy remain unclear. Methods: From October 2008 to April 2015, 93 patients with TTTS who received fetoscopic laser therapy at our hospital were included in this study, and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were measured within 24 h before therapy. If ELEzs (AST > 34 U/L or ALT > 36 U/L) were observed before therapy, the AST and ALT levels were evaluated within 24 h after therapy. The pre-operative characteristics and post-therapy outcomes were compared between patients with and without ELEzs. Results: Among 93 TTTS patients before laser operation, 18 patients (were found with ELEzs (19.4%) before laser therapy. In 17 (94.4%) of the 18 cases, their liver enzymes values dropped after laser surgery. Maternal body mass index, age, gestational age of laser therapy, hemoglobin level before laser therapy and survival rates after laser therapy were not significantly different between TTTS with and without ELEzs. The maternal hemoglobin dropped significantly from 10.8 [1.6] g/dL before surgery to 9.6 [1.5] g/dL after laser therapy in TTTS with ELEzs (p < 0.001). Conclusion: An elevated liver enzyme was not associated with poor perinatal outcomes in patients with TTTS after laser therapy. The authors suspected that the reduced liver enzymes values after laser therapy could partly arise from the hemo-dilution effect.